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.
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.