Beat Frequency Calculator

How to Use This Calculator

1. Enter Frequency 1 and Frequency 2 to get beat frequency and beat period.
2. Use Tuning tab — enter target pitch and observed beat rate to find corrected frequencies in Hz and cents.
3. Use Musical Intervals tab to see octave, fifth, fourth, and third relationships.
4. Switch to Professional for cents deviation, A4 tuning analysis, and harmonic beats.

Formula

Example

Frequently Asked Questions

• What is beat frequency? ▼
  Beat frequency is the audible pulsation heard when two sound waves of slightly different frequencies interfere. Beat frequency = |f₁ − f₂|. The beats per second equals the frequency difference.
• Why do musicians use beats to tune instruments? ▼
  When two notes are slightly out of tune, beats slow as the pitch converges. At zero beats the notes match. Tuning to eliminate beats is one of the most precise aural tuning methods available.
• What is a cents deviation? ▼
  A cent is 1/100 of a semitone (1/1200 of an octave). Cents deviation = 1200 × log₂(f_observed / f_reference). The human ear can detect deviations of 5–10 cents.
• What is a perfect fifth in terms of frequency ratio? ▼
  A just perfect fifth has a 3:2 frequency ratio. In equal temperament (12-TET), it is 2^(7/12) ≈ 1.4983, which is 1.96 cents lower than the pure 3:2 ratio — this small difference produces slow, pleasant beats.
• How do harmonics affect beats? ▼
  Beats occur not just at the fundamental frequency but also at each harmonic. The nth harmonic of two close pitches produces beats at n × |f₁ − f₂|. Higher harmonics produce faster, more audible beats.

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