BPMCalculator.site
Translate musical sync into a cycle rate
An LFO sync calculator connects a musical division to two technical descriptions of one theoretical cycle: its period in time and its frequency in hertz. It begins with a declared tempo beat, so it can also handle cases where BPM counts something other than a quarter note.
The page does not create an oscillator. Its output is a timing reference for controls that accept seconds, milliseconds, or cycles per second.
Period comes before frequency
The tempo reference period is 60 ÷ BPM seconds. Rational note proportions convert it to the chosen cycle division. Dotted multiplies the straight division by 3/2; triplet multiplies it by 2/3.
Frequency equals 1 ÷ period seconds. A one-second cycle is 1 hertz. A half-second cycle is 2 hertz. Because the relationship is reciprocal, a longer synchronized division produces a lower frequency.
The page also expresses cycles per supplied tempo beat and supplied beats per cycle. Those ratios expose whether the selected cycle is faster or slower than the declared pulse.
Worked straight-quarter example
Enter 120 quarter-note BPM and choose a straight quarter cycle. One quarter lasts 60 ÷ 120 = 0.5 seconds, or 500 milliseconds. Its frequency is 1 ÷ 0.5 = 2 hertz.
There is one cycle per supplied beat and one supplied beat per cycle. This is the simplest reference state and the reset default.
Worked dotted-quarter example
Keep 120 quarter-note BPM but select dotted quarter. The straight quarter is 500 milliseconds; multiplying by 3/2 gives a 750-millisecond cycle. Frequency is 1 ÷ 0.75, approximately 1.333333 hertz.
The cycle lasts 1.5 supplied quarter beats, so there are two thirds of a cycle per beat. Those ratios describe timing only. They do not imply a waveform phase begins at a particular barline.
Sync labels differ across devices
A device may describe a synchronized setting as the duration of one complete modulation cycle, the step time within a sequence, or a multiplier relative to host tempo. A displayed “1/4” can therefore behave differently across products.
Before copying hertz, verify that the destination expects one full cycle at the chosen note duration. Check whether its frequency input is free-running, host-synced, retriggered, or tempo-automated.
Phase, waveform, and depth are excluded
Frequency does not define phase. Two 2-Hz oscillators can be offset in time. It also does not specify sine, triangle, square, random, sample-and-hold, duty cycle, smoothing, or modulation depth.
The calculator has no preview because a visual or audible oscillator would introduce another product action. It offers only the period relationship that can be audited.
Tempo automation
One constant BPM governs the output. A host-synced LFO may update continuously, at a bar boundary, on transport start, or according to smoothing rules when tempo changes. A free-running hertz value may ignore later tempo changes entirely.
The page cannot predict those behaviors. Recalculate each stable rate and test transitions in the destination.
Precision and implementation
Long decimal frequencies are formatted only after the unrounded period is calculated. If the destination accepts fewer decimals, it may produce a slightly different cycle length over time. Preserve both period and frequency so the rounding effect can be checked.
Discrete control rates and sample clocks add another layer. This route does not quantize frequency to a processing block or sample boundary.
Local and temporary
No oscillator state, project tempo, MIDI clock, or host transport is read. Inputs and output cards remain in current page memory. Reset returns to the 2-Hz demonstration and clears copied notices.
Compare period after frequency rounding
Suppose the theoretical result is 1.333333 hertz and a destination accepts only 1.33. Its represented period becomes 1 ÷ 1.33, approximately 0.75188 seconds rather than exactly 0.75. The difference is small for one cycle but can change phase relative to a grid over a long span.
If the destination accepts period with greater precision than frequency, milliseconds may be the better transfer field. If it accepts only a synchronized note label, retain the label and let the destination follow its own host clock. The calculator exposes options but cannot know which path is authoritative.
Before entering a value
Identify whether the destination number means a full cycle or a step. Check its expected unit and rounding. Decide whether phase retriggers at transport or note events. Then copy the output whose definition matches. These checks prevent a correct reciprocal from being applied to a different modulation concept.
Frequently asked questions
Is LFO frequency the same as pitch?
Hertz uses the same unit, but this page describes a slow modulation cycle, not a musical pitch source.
Why is a dotted division slower?
Its period is 1.5 times the straight duration, so its reciprocal frequency is two thirds as large.
Does the result synchronize phase?
No. It gives period and rate; phase and retrigger behavior belong to the destination.
Can I hear the cycle here?
No. The tool creates neither audio nor an oscillator signal.
Choose the cycle convention, calculate both period and hertz, and confirm what one cycle means in the system receiving the value.