Metronome Calculator

How to Use This Calculator

1. Enter your BPM and select the Beats per Measure (time signature).
2. See the measure duration in seconds and beat interval in milliseconds.
3. Use the Subdivisions tab for eighth note, sixteenth note, and swing timing.
4. Use the Polyrhythm tab to calculate 3-against-4, 5-against-4, or any ratio.

Formula

Example

Frequently Asked Questions

• How long is a measure at 120 BPM in 4/4? ▼
  At 120 BPM, one beat = 500 ms. In 4/4, a measure contains 4 beats, so measure duration = 4 × 500 ms = 2,000 ms (2 seconds).
• What is a polyrhythm? ▼
  A polyrhythm occurs when two different rhythmic patterns play simultaneously over the same time window. A 3-against-4 polyrhythm means fitting 3 evenly-spaced beats in the same time as 4 beats. Each rhythm has a different interval but they coincide on beat 1.
• What is a swing rhythm? ▼
  Swing divides each beat into a long-short pair (roughly 2/3 + 1/3 of the beat) instead of even 50/50 eighth notes. At 120 BPM, a straight eighth = 250 ms; a swing pair = 333 ms + 167 ms.
• How should I practice increasing BPM? ▼
  Start at 60–70% of your target tempo, play 3–5 minutes until comfortable, then increase by 5–10 BPM. This builds muscle memory gradually. Never jump to the target tempo before mastering each intermediate step.

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