Duration Calculator

Tempo, note value, clock time — solve for any.

Calcophony Duration Calculator showing note values converted to milliseconds and SMPTE timecode

Three variables, one equation

Tempo, note value, and duration are linked by a single equation: duration = (60 / BPM) × note-value-ratio. Fix any two, the third falls out. The Duration Calculator lets you pick which variable you're solving for — find the duration given a tempo and note value, find the tempo that makes a note value last a specified time, or find which note value matches a target duration at a given tempo.

Three modes

Batch mode

For film-scoring and post-production, batch mode tabulates every standard note value at a given tempo in one pass. At 120 BPM, a whole note is 2000 ms (00:02.000), a quarter is 500 ms (00:00.500), a 32nd is 62.5 ms (00:00.063). Scan the list to find which division gets you closest to a hit point or sync mark — no division, no rounding, no spreadsheet.

SMPTE timecode

Durations are shown in SMPTE-style MM:SS.mmm format alongside raw milliseconds and seconds. This is the format film-scoring sessions use to mark hit points, and the format most DAWs expose for region positions.

When to use it

Scoring to picture and you need a phrase of exactly 4.200 seconds — the batch list tells you whether a dotted half at 107 BPM lands closer than a whole note at 114 BPM. Tuning a delay time to an eighth-note at 128 BPM (234.375 ms). Setting a sample length. Checking that a silence in a part is really the length the composer intended. For nested-tuplet durations specifically, use Rhythm & Subdivision.

Related modules

See all modules →