ToolsBPM maths
Audio / BPM maths
BPM Maths
The numbers you keep working out on a phone calculator mid-session: note values in milliseconds for delays, in hertz for LFOs, reverb times that land on the grid, and how long eight bars actually is.
Note values
| Note | Straight | Dotted | Triplet | LFO rate |
|---|
Reverb starting points
| Character | Pre-delay | Decay |
|---|
Conventions, not rules: pre-delay keeps the transient in front of the wash, decay in whole bars keeps the tail rhythmic. Tune by ear from here.
Length converters
Pitch converter
About this tool
BPM Maths turns a tempo into every number you'd otherwise work out on a phone calculator mid-session — note values in milliseconds for delays, in hertz for LFOs, reverb pre-delay and decay starting points that land on the grid, bars converted to seconds and samples, and Hz converted to note, MIDI and cents. Tap the tempo or type it directly.
How to use it
- Type a BPM or tap the tempo button in time.
- Read note values in milliseconds and hertz for delay and LFO settings.
- Check reverb pre-delay and decay starting points for that tempo.
- Convert bars to seconds/samples or Hz to note/MIDI/cents as needed.
FAQ
Is this free?
Yes — every calculation here is free and unlimited.
Is it accurate enough for mixing decisions?
Yes — the note-value maths is exact; use it as your starting point and trust your ears from there.
Does it store the tempos I use?
No — nothing is uploaded; it's a live calculator only.
Can I tap in a tempo instead of typing it?
Yes — tap tempo is built in.
A4 = 440 Hz. Wavelength assumes 343 m/s, handy for room modes and mic placement.