BPM Tempo Calculator
Calculate how many seconds a musical passage takes based on BPM, time signature, note value, and number of measures. Use it for syncing audio to video, setting delay times, or planning arrangement lengths.
Last updated: May 2026
About this calculator
Musical time is determined by tempo (BPM), meter (time signature), and note subdivision. The duration of a passage in seconds is: time = (measures × timeSignature × 60) / (bpm × noteValue), where measures is the number of bars, timeSignature is the number of beats per bar (e.g., 4 for 4/4), 60 converts BPM to seconds per beat, and noteValue represents the subdivision relative to a quarter note (e.g., 1 for quarter notes, 0.5 for eighth notes, 2 for half notes). A single beat at 120 BPM lasts exactly 0.5 seconds (60/120). Understanding this relationship helps producers sync music to picture, calculate delay and reverb pre-delay in milliseconds, and predict the total runtime of a composition before recording.
How to use
You want to know how long an 8-bar intro lasts at 95 BPM in 4/4 time with quarter-note beats. Set measures = 8, timeSignature = 4, bpm = 95, noteValue = 1. Step 1: Numerator = 8 × 4 × 60 = 1,920. Step 2: Denominator = 95 × 1 = 95. Step 3: time = 1,920 / 95 ≈ 20.2 seconds. Now try noteValue = 0.5 (eighth-note grid): time = 1,920 / (95 × 0.5) ≈ 40.4 seconds — twice as long because you are counting twice as many subdivisions. The quarter-note result (20.2 s) is the actual clock duration of 8 bars at 95 BPM.
Frequently asked questions
How do I calculate the millisecond delay time for a dotted-eighth note delay at a given BPM?
A quarter note at X BPM lasts 60,000 / X milliseconds. A dotted-eighth note is 75% of a quarter note, so dotted-eighth delay = (60,000 / BPM) × 0.75. At 120 BPM: 60,000 / 120 = 500 ms per beat; 500 × 0.75 = 375 ms. This is the classic 'Edge delay' value used in songs like Where The Streets Have No Name. Plugging this into a digital delay pedal or DAW plugin creates a rhythmically locked slap-back effect that grooves with the tempo.
What is the difference between BPM and time signature in music?
BPM (beats per minute) measures the speed of the pulse — how many beats occur in 60 seconds. Time signature defines how those beats are grouped into bars; 4/4 means 4 quarter-note beats per bar, 3/4 means 3, and 6/8 groups six eighth-note beats into two felt pulses. Changing the time signature at the same BPM does not alter the speed of individual beats but does change the length of a measure and the position of strong and weak beats. A waltz in 3/4 at 120 BPM has bars that are 1.5 seconds long, while 4/4 at 120 BPM gives 2-second bars.
How do I sync music tempo to a specific video scene duration?
If your video scene is exactly 24 seconds long and you want it to fill a whole number of 4-bar phrases, rearrange the formula: BPM = (measures × timeSignature × 60) / (time × noteValue). For 4 bars in 4/4 over 24 seconds: BPM = (4 × 4 × 60) / (24 × 1) = 960 / 24 = 40 BPM. For 8 bars: BPM = 1920 / 24 = 80 BPM. Choose 8 bars at 80 BPM for a more natural tempo. This technique ensures music hits and phrases land cleanly on scene cuts without the need for time-stretching.