BPM & Tempo Calculator

Beats Per Minute (BPM) and tempo calculations form the mathematical bridge between musical timing and acoustic physics, translating the rhythmic pulse of a song into precise measurements of milliseconds and Hertz. Understanding how to convert tempo into exact time values is essential for music producers, audio engineers, and sound designers who need to synchronize delay effects, calculate reverb pre-delays, set compressor release times, and align low-frequency oscillators (LFOs). By mastering these conversions, anyone working with audio can transform chaotic, overlapping sounds into a cohesive, rhythmic landscape where every technical parameter breathes in perfect harmony with the music.

What It Is and Why It Matters

At its absolute core, tempo is the speed or pace of a given piece of music, universally measured in Beats Per Minute (BPM). If a song has a tempo of 60 BPM, there is exactly one beat every second. However, modern audio production requires a level of precision that extends far beyond simply tapping a foot to a beat. Audio effects, synthesizers, and dynamic processors operate in the realm of absolute time—specifically milliseconds (ms) and frequencies (Hz)—rather than abstract musical notation. A BPM and tempo calculation is the mathematical process of translating a musical tempo into these absolute acoustic measurements. This conversion dictates exactly how long a quarter note, an eighth note, or a sixteenth note lasts in actual time.

This calculation matters because the human brain is exceptionally sensitive to rhythmic anomalies. When an audio engineer applies an echo (delay) to a vocal track, that echo must repeat in time with the song's tempo. If the song is playing at 120 BPM, and the delay is set to repeat every 412 milliseconds, the echo will clash with the underlying rhythm, creating a muddy, chaotic, and unmusical mess. Conversely, if the delay is mathematically calculated to repeat every 500 milliseconds (the exact duration of a quarter note at 120 BPM), the echo will perfectly reinforce the song's groove.

Beyond simple delays, this concept solves complex problems across the entire spectrum of sound design and mixing. It allows producers to calculate the precise release time for a compressor so that it stops reducing volume exactly when the next kick drum hits. It enables synthesizer programmers to set an LFO to modulate a filter exactly three times per beat. Without the ability to calculate tempo into milliseconds and Hertz, audio production relies entirely on blind guesswork. By understanding these calculations, a complete novice can immediately elevate their mixes, ensuring that every spatial effect and dynamic movement locks tightly into the musical grid, resulting in professional, polished, and rhythmically driving audio.

History and Origin

The human desire to measure and standardize musical time dates back centuries, long before the invention of digital audio workstations or electronic calculators. The conceptual foundation began in 1581 when Galileo Galilei discovered the isochronism of pendulums, noting that a pendulum takes the same amount of time to complete a swing regardless of its amplitude. This discovery laid the groundwork for mechanical timekeeping. However, it was not until 1815 that a German inventor named Johann Nepomuk Maelzel patented the mechanical metronome. Maelzel’s device allowed composers, most notably Ludwig van Beethoven, to prescribe exact tempos for their compositions using numerical values—Beats Per Minute—rather than vague Italian terms like "Allegro" or "Adagio."

For over a century, BPM remained strictly a tool for musicians to keep time. The necessity to translate BPM into milliseconds did not arise until the mid-20th century with the advent of magnetic tape recording. In the 1950s and 1960s, pioneering producers like Sam Phillips and Lee "Scratch" Perry began using tape machines to create "slapback" and dub delays. Because tape delay relies on the physical distance between the record and playback heads, engineers had to calculate the tape speed—measured in inches per second (IPS)—against the song's tempo to achieve rhythmic echoes. This required complex manual mathematics, measuring physical tape with rulers to align the acoustic reflections with the drummer's groove.

The true revolution occurred in the late 1970s and early 1980s with the introduction of digital delay units, such as the legendary Lexicon PCM42 and the Roland SDE-3000. These hardware units allowed engineers to input delay times digitally, but they required those inputs to be in pure milliseconds. Because these early units lacked the "Sync to Host" buttons found in modern software, engineers kept printed cheat sheets of BPM-to-millisecond conversion charts taped to their mixing consoles. In 1983, the introduction of the Musical Instrument Digital Interface (MIDI) standard further solidified the need for exact mathematical relationships between tempo and time, as drum machines and synthesizers needed to communicate clock signals. Today, while software can automate many of these calculations, the underlying mathematics remain identical to those used by the pioneers of electronic music, and understanding the history illuminates why these specific measurements are still the industry standard.

Key Concepts and Terminology

To master tempo calculations, one must first build a robust vocabulary of the underlying concepts. Without a firm grasp of these terms, the mathematical formulas will lack context.

Beats Per Minute (BPM): The universal unit of measurement for musical tempo. It defines how many quarter-note beats occur in exactly 60 seconds. A tempo of 120 BPM means there are 120 beats per minute, or two beats per second.

Milliseconds (ms): A unit of time equal to one-thousandth of a second. There are 1,000 milliseconds in one second, and 60,000 milliseconds in one minute. In audio production, milliseconds are the standard unit for measuring delay times, reverb decay, and compressor attack/release parameters.

Hertz (Hz): A unit of frequency measuring the number of cycles per second. While BPM measures beats per minute, Hz measures events per second. In tempo calculations, Hz is used to synchronize Low-Frequency Oscillators (LFOs) so that synthesizer modulations pulse in time with the track.

Note Values (Straight): The standard divisions of musical time. A whole note occupies an entire four-beat measure. A half note occupies two beats. A quarter note occupies one beat. Eighth notes divide the beat in half, and sixteenth notes divide the beat into four equal parts.

Dotted Notes: A musical modifier that increases the duration of a standard note by exactly 50%. A dotted quarter note is equal to a quarter note plus an eighth note (1.5 times the length of a quarter note). Dotted notes are crucial for creating syncopated, bouncing rhythms that play "off" the primary grid.

Triplets: A musical modifier that divides a standard note value into three equal parts instead of two. An eighth-note triplet squeezes three notes into the space normally occupied by two eighth notes. Mathematically, a triplet is exactly 66.666% (or two-thirds) the duration of its straight counterpart. Triplets create a rolling, swinging, or waltzing feel.

Pre-Delay: The short amount of time (measured in milliseconds) between the original dry sound and the onset of an artificial reverb. Calculating pre-delay based on tempo allows the original sound to cut through the mix before the reverberation washes over it.

How It Works — Step by Step

The process of converting a musical tempo into a precise millisecond value relies on a straightforward, universally applicable mathematical formula. Because there are 60 seconds in a minute, and 1,000 milliseconds in a second, there are exactly 60,000 milliseconds in one minute. By dividing this constant number by the BPM, we determine the exact duration of a single beat (a quarter note) in milliseconds.

The Core Formula

The foundation of all tempo math is the Quarter Note Formula: Quarter Note (ms) = 60,000 / BPM

Once the quarter note duration is established, all other note values are derived through simple multiplication or division.

Half Note: Quarter Note × 2
Whole Note: Quarter Note × 4
Eighth Note: Quarter Note / 2
Sixteenth Note: Quarter Note / 4

To calculate modified notes, you apply a multiplier to the straight note value:

Dotted Note Multiplier: Multiply the straight note value by 1.5.
Triplet Note Multiplier: Multiply the straight note value by 0.6666 (or multiply by 2, then divide by 3).

Full Worked Example

Imagine you are producing a modern electronic track at exactly 128 BPM. You want to calculate the millisecond values for a quarter note, an eighth note, a dotted eighth note, and a sixteenth-note triplet.

Step 1: Find the Quarter Note Divide the constant (60,000) by the tempo (128). 60,000 / 128 = 468.75 ms A single quarter note lasts exactly 468.75 milliseconds.

Step 2: Find the Eighth Note Divide the quarter note value by 2. 468.75 / 2 = 234.375 ms An eighth note lasts exactly 234.375 milliseconds.

Step 3: Find the Dotted Eighth Note Take the straight eighth note value and multiply it by 1.5. 234.375 × 1.5 = 351.5625 ms A dotted eighth note lasts exactly 351.56 milliseconds. (Most hardware units round to 352 ms).

Step 4: Find the Sixteenth Note Triplet First, find the straight sixteenth note by dividing the quarter note by 4. 468.75 / 4 = 117.1875 ms. Next, multiply the sixteenth note by 0.6666 (or multiply by 2 and divide by 3). 117.1875 × 2 = 234.375. 234.375 / 3 = 78.125 ms A sixteenth-note triplet lasts exactly 78.125 milliseconds.

By writing down these specific numbers, an engineer can manually input them into any vintage hardware, digital plugin, or synthesizer to ensure perfect rhythmic synchronization.

Types, Variations, and Methods

Tempo calculations generally fall into three distinct rhythmic categories, each serving a drastically different aesthetic purpose in music production. Understanding when to use straight, dotted, or triplet times is what separates an amateur sound designer from an expert.

Straight Time Calculations

Straight time refers to standard binary subdivisions: whole, half, quarter, eighth, sixteenth, and thirty-second notes. Calculating straight time yields delays and modulations that land exactly on the rigid grid of the music. This method is predominantly used to reinforce the existing groove without adding new rhythmic complexity. For example, a straight quarter-note delay on a vocal will hide neatly behind the vocal itself, creating a sense of depth and size without distracting the listener. Straight time is the bedrock of four-on-the-floor dance music, rock, and traditional pop.

Dotted Time Calculations

Dotted notes are the secret weapon of rhythmic delay. Because a dotted note is 1.5 times the length of a straight note, a dotted-eighth delay will fall precisely halfway between the straight eighth notes and the quarter notes. This creates a highly syncopated, bouncing rhythm that interacts with the original audio to create complex, interlocking patterns. The most famous application of this method is the guitar playing of The Edge from U2. By playing simple, straight eighth notes into a delay set to a dotted-eighth millisecond value, the resulting sound is a cascading, sixteenth-note rhythm that sounds incredibly complex but is mechanically very simple.

Triplet Time Calculations

Triplet calculations divide the beat into threes, resulting in a swinging, rolling, or waltzing feel. Triplets are frequently used in blues, jazz, hip-hop, and certain subgenres of electronic music like dubstep and trap. Using a triplet delay calculation on a straight-time vocal can add a subtle, polyrhythmic swing that loosens up a rigid track. Conversely, if a song is already written with a triplet swing (often called a 6/8 or 12/8 time signature), you must use triplet millisecond calculations for your effects; using straight-time calculations on a swinging track will cause catastrophic rhythmic clashing.

Frequency (Hz) Calculations

While milliseconds govern time, Hertz (Hz) governs frequency. Synthesizers use Low-Frequency Oscillators (LFOs) to modulate volume, pitch, or filters. If you want a synthesizer "wobble" to pulse exactly four times per beat, you must convert BPM to Hz. The formula is: Hz = BPM / 60. If your track is 120 BPM, dividing by 60 gives you 2 Hz. This means a 2 Hz LFO will complete exactly two full cycles per second, perfectly matching the quarter-note pulse of a 120 BPM song. To make the LFO pulse twice as fast (eighth notes), you simply double the Hz to 4 Hz.

Real-World Examples and Applications

To truly grasp the power of BPM and tempo calculations, one must examine how these numbers are applied in professional mixing and sound design environments. The mathematics are useless without practical application.

Scenario 1: The Rhythmic Delay Throw A mix engineer is working on a pop vocal track at 105 BPM. The vocalist sings a phrase that ends abruptly, leaving a large gap of silence before the chorus. The engineer wants a dramatic, cascading echo to fill this gap. Using the formula (60,000 / 105), the quarter note is calculated at 571.42 ms. To create a bouncing, syncopated feel, the engineer calculates a dotted-eighth note: (571.42 / 2) * 1.5 = 428.57 ms. The engineer sets the digital delay plugin to exactly 428.6 ms with high feedback. The resulting vocal echoes cascade flawlessly into the silence, creating excitement without stepping on the rhythm of the upcoming chorus.

Scenario 2: Snare Reverb Pre-Delay A rock producer is mixing a snare drum in a 90 BPM track. They apply a massive, 3-second hall reverb to make the snare sound huge, but the reverb instantly washes out the initial "crack" of the drum stick hitting the skin. The solution is pre-delay—delaying the onset of the reverb. The producer decides a 1/64th note gap will be enough to let the transient punch through. At 90 BPM, a quarter note is 666.66 ms. An eighth is 333.33 ms, a sixteenth is 166.66 ms, a thirty-second is 83.33 ms, and a sixty-fourth is 41.66 ms. The producer sets the reverb pre-delay to 42 ms. Now, the snare hits with total clarity, and exactly 42 milliseconds later, the massive reverb blooms, perfectly in time with the microscopic subdivisions of the song.

Scenario 3: EDM Sidechain Compression Release A house music producer is working at 125 BPM and using sidechain compression to "duck" the volume of the bass synthesizer every time the kick drum hits. For the track to groove properly, the bass volume must return to normal just before the next eighth note occurs. At 125 BPM, a quarter note is 480 ms, and an eighth note is 240 ms. The producer sets the compressor's release time to exactly 235 ms (leaving a tiny 5 ms buffer). The result is a mix that breathes rhythmically; the bass ducks out of the way of the kick, and swells back up to full volume precisely in time for the off-beat, creating a massive, pumping dancefloor groove.

Common Mistakes and Misconceptions

Despite the mathematical certainty of tempo calculations, beginners frequently fall into several conceptual traps that can ruin a mix.

Misconception 1: "Sync" Buttons Make Math Obsolete Modern software plugins almost universally feature a "Sync to Host" button, which automatically locks the delay or LFO to the DAW's tempo. Beginners assume this renders manual math obsolete. This is a massive mistake. Sync buttons lock you exclusively to rigid, perfect mathematical grids. They do not allow for the subtle humanization of pushing a delay 5 milliseconds late to create width, or pulling an LFO slightly ahead of the beat to create urgency. Relying purely on sync buttons leads to sterile, robotic mixes. Professionals use manual millisecond calculations as a baseline, and then intentionally deviate from them.

Misconception 2: Confusing Swing with Triplets Many novices assume that if a track has "swing," they must use exact triplet calculations for their delays. While hard swing is mathematically similar to a triplet, most hip-hop and house swing is actually a percentage offset (e.g., 55% to 65% swing). If a producer applies a rigid 66.6% triplet delay to a track with a 58% MPC-style swing, the delay will painfully clash with the groove. In these cases, the producer must calculate the straight eighth note, and then manually adjust the milliseconds by ear to match the specific swing percentage.

Misconception 3: Ignoring the Pitch of the Sound A common mistake is applying mathematically perfect delay times to low-frequency sounds (like bass guitars or kick drums) and wondering why it sounds terrible. Low frequencies have very long physical waveforms. A 40 Hz sub-bass wave takes 25 milliseconds just to complete a single cycle. If you set a delay or a compressor attack time to 10 milliseconds on a sub-bass, you are interrupting the waveform before it even finishes, causing clicks, pops, and phase cancellation. Mathematical perfection must always be cross-referenced with acoustic physics.

Best Practices and Expert Strategies

Professionals do not just use tempo calculations to keep things tidy; they use them as a foundation for advanced psychoacoustic manipulation. By mastering the rules, experts learn exactly how to break them.

The Haas Effect and Stereo Widening Experts use tempo calculations in conjunction with the Haas Effect (also known as the precedence effect) to create massive stereo width. The human ear perceives two identical sounds separated by less than roughly 35 milliseconds as a single, wide sound rather than a distinct echo. A professional might calculate a straight sixteenth-note delay (e.g., 125 ms), but set the left channel to 125 ms and the right channel to 132 ms (a 7 ms offset). Because the offset is within the Haas threshold, the listener does not hear two separate echoes; instead, they hear one perfectly timed echo that sounds incredibly wide and spacious.

Intentional Rhythmic Offsets (Push and Pull) Perfect math can feel sterile. Expert producers frequently calculate the exact millisecond value of a beat and then intentionally offset it to manipulate the emotional feel of a track. If a song's quarter note is 500 ms, setting a snare reverb pre-delay to 510 ms (slightly late) will make the song feel relaxed, lazy, and laid-back—perfect for lo-fi hip hop or neo-soul. Conversely, setting an arpeggiator to 490 ms (slightly early) will push the beat, creating a sense of urgency, anxiety, and forward momentum ideal for aggressive techno or punk rock.

Polyrhythmic Layering Instead of using a single delay, experts layer multiple delays using different mathematical subdivisions to create polyrhythms. For example, routing a synthesizer into one delay set to a dotted-eighth (3/16ths) and another delay set to a straight quarter note (4/16ths). These two echoes will play against each other, mathematically intersecting and diverging, turning a single sustained note into a complex, evolving rhythmic sequence. Because both values are derived from the same master BPM calculation, they will never clash, but they will create immense musical interest.

Edge Cases, Limitations, and Pitfalls

While the 60,000 / BPM formula is infallible in a vacuum, real-world music production is fraught with edge cases where strict adherence to the math will lead to disastrous results.

Live Instrumentation and Tempo Drift The most significant limitation of tempo calculation is music recorded without a click track. A live rock band or a classical orchestra naturally speeds up during choruses and slows down during verses—a phenomenon known as tempo drift or rubato. If a band's tempo fluctuates between 112 BPM and 118 BPM over the course of a song, calculating a static delay time based on an average of 115 BPM will result in echoes that are out of time for the entire track. In these edge cases, engineers must either use dynamic tempo mapping within their software to constantly update the mathematical baseline, or rely entirely on "tap tempo" and their own ears.

Floating-Point Rounding Errors A hidden pitfall in digital audio is rounding errors. As seen in the earlier math example, a sixteenth-note triplet at 128 BPM is 78.125 milliseconds. However, many vintage digital delays and even some modern guitar pedals only accept whole numbers (integers) for millisecond inputs. If the hardware forces you to round 78.125 ms to 78 ms, the delay will be off by 0.125 milliseconds per repeat. While this sounds microscopic, if you set the delay to have a high feedback (repeating 20 or 30 times), that tiny error multiplies exponentially. By the 20th repeat, the echo is 2.5 milliseconds out of time, which is enough to cause audible phase smearing.

Extreme Tempos The math begins to lose its musical utility at extreme tempo boundaries. In genres like Speedcore or Extratone, where tempos can exceed 400 to 1,000 BPM, the calculated millisecond values for notes become so short that they enter the audio rate. For instance, at 600 BPM, a quarter note is 100 ms, and a sixteenth note is just 25 ms. At 25 milliseconds, the human ear stops perceiving individual rhythmic hits and begins hearing a continuous low-frequency pitch (40 Hz). Attempting to calculate and apply standard rhythmic delays at these extremes is pointless, as the physics of human hearing transition from rhythm perception to pitch perception.

Industry Standards and Benchmarks

While tempo is subjective, the music industry has gravitated toward specific BPM ranges and delay standards that have shaped the sound of modern genres. Knowing these benchmarks allows a producer to calculate times that meet listener expectations.

Standard Genre Tempos:

House / Techno: 120 to 128 BPM. The mathematical benchmark of EDM is 128 BPM, making the 468.75 ms quarter note one of the most frequently calculated numbers in electronic music.
Hip-Hop / Boom Bap: 85 to 95 BPM. Quarter notes range from 705 ms to 631 ms, allowing for long, sweeping grooves and deep pocket swing.
Trap / Dubstep: 140 to 150 BPM (often felt in half-time at 70 to 75 BPM). Calculations here frequently rely on triplet subdivisions to accommodate the rapid hi-hat rolls characteristic of the genre.
Pop: 100 to 120 BPM, providing an energetic but danceable mathematical framework.

Industry Standard Delay Applications:

The "Slapback" Echo: A staple of rockabilly and country vocals, slapback is universally set between 80 ms and 120 ms. Unlike rhythmic delays, slapback is often set independently of the BPM calculation to provide a static sense of small-room space.
The Vocal "Throw": In modern pop, engineers typically calculate a 1/4 note or 1/2 note delay (often between 500 ms and 1000 ms) to fill the gaps at the end of vocal phrases.
Reverb Decay Times: For a standard mix, a snare drum reverb decay is typically benchmarked to last exactly the length of one quarter note or one half note, ensuring the reverb completely dies out before the next major downbeat occurs.

Comparisons with Alternatives

When it comes to syncing time-based effects, manual BPM-to-millisecond calculation is not the only method available. Understanding how it compares to the alternatives is crucial for determining the right tool for the job.

Manual Calculation vs. DAW Auto-Sync DAW Auto-Sync is the modern default. By clicking a button, the plugin reads the host tempo and automatically adjusts its parameters.

Pros of Auto-Sync: Instantaneous workflow. Automatically tracks tempo changes and time signature shifts perfectly. Eliminates human math errors.
Cons of Auto-Sync: Rigid and inflexible. Prevents intentional micro-timing offsets. Locks you into standard subdivisions provided by the plugin developer.
The Verdict: Auto-sync is best for rapid drafting and composition. Manual calculation is vastly superior for the final mixdown stage, where micro-timing and humanization (pushing/pulling the beat by 2-5 ms) are required for a professional polish.

Manual Calculation vs. Tap Tempo Tap Tempo allows a user to tap a physical button or footswitch in time with the music; the hardware or software then calculates the average time between taps and sets the milliseconds accordingly.

Pros of Tap Tempo: Essential for live performances without a click track. Highly musical, as it relies on human feel rather than a rigid grid.
Cons of Tap Tempo: Inherently imprecise. A human might tap 495 ms, 503 ms, and 512 ms, resulting in an average that is slightly off the true tempo. Useless for precise studio sidechain compression or LFO syncing.
The Verdict: Tap tempo is the undisputed king of live stage performance. Manual calculation is the undisputed king of the recording studio.

Manual Calculation vs. Visual Waveform Alignment Some producers ignore math entirely and visually drag audio clips (like a recorded delay tail) on the DAW timeline until the peaks line up with the grid lines.

Pros of Visual Alignment: What you see is what you get. Accounts for the actual acoustic transient of the sound rather than theoretical math.
Cons of Visual Alignment: Incredibly time-consuming. Does not work for hardware effects, LFOs, or compressor release times where there is no waveform to drag.
The Verdict: Visual alignment is a great secondary check to confirm your math, but it is too slow and limited to replace mathematical calculation as a primary workflow.

Frequently Asked Questions

How do I find the BPM of a sample or song if I don't know it? To find the BPM of an unknown piece of audio, you can use a few different methods. The simplest is to use a tap tempo tool, tapping along to the quarter-note pulse of the song for about 15 seconds to get an accurate average. Alternatively, most modern DAWs feature auto-detection algorithms that analyze the transients (spikes in volume) of an audio file to calculate the tempo. If you want to do it manually, you can count the number of beats that occur in exactly 15 seconds and multiply that number by 4 to get the Beats Per Minute.

Why do my mathematically perfect delays still sound messy in the mix? If your math is perfect but the mix sounds chaotic, you are likely suffering from frequency masking or excessive feedback. A delay that accurately repeats a vocal will also repeat all the low-mid frequencies of that vocal, causing mud. To fix this, apply a High-Pass Filter (HPF) and a Low-Pass Filter (LPF) to the delayed signal—often called the "Abbey Road EQ trick." By filtering out the extreme lows and highs of the echo, the delay sits cleanly behind the dry vocal, maintaining rhythmic perfection without cluttering the frequency spectrum.

Can I use these BPM calculations for video editing? Absolutely. Video editors frequently use BPM math to sync visual cuts to the beat of a soundtrack. However, video is measured in Frames Per Second (FPS) rather than milliseconds. To calculate this, divide the BPM by 60 to get Beats Per Second, then divide your video framerate (e.g., 24 FPS) by the Beats Per Second. For a 120 BPM song at 24 FPS, a beat occurs exactly every 12 frames. Knowing this allows an editor to mathematically place cuts precisely on the downbeat without relying solely on visual waveforms.

What is the Haas effect and how does it relate to milliseconds? The Haas effect, or precedence effect, is a psychoacoustic phenomenon where the human ear perceives two identical sounds separated by less than roughly 35 milliseconds as a single, unified sound. If the delay time is longer than 35 ms, the brain hears it as a distinct echo. Producers use this by panning a dry signal strictly to the left, and a delayed signal (e.g., 20 ms) strictly to the right. Because the delay is under the Haas threshold, it doesn't sound like an echo; instead, the brain perceives a single, incredibly wide sound source.

How do I calculate Hertz (Hz) from BPM for my synthesizer LFOs? To convert BPM into Hertz, you divide the BPM by 60. This gives you the frequency for a quarter note. For example, if your track is 140 BPM, dividing by 60 gives you 2.33 Hz. This means an LFO set to 2.33 Hz will complete one full cycle per beat. To find the Hz for an eighth note, you multiply that result by 2 (4.66 Hz). To find the Hz for a half note, you divide the quarter note result by 2 (1.16 Hz). This ensures your synth modulations pulse perfectly in time with the track.

Why do some hardware units round my calculated milliseconds? Many vintage digital delay units, and even some modern digital emulations, process time using integer values rather than floating-point numbers. This means they cannot comprehend fractions of a millisecond. If your calculation results in 351.56 ms, the hardware forces you to input either 351 or 352. In almost all musical contexts, a deviation of less than half a millisecond is entirely imperceptible to the human ear and will not negatively impact the groove of the song. You should always round to the nearest whole number.