Enter two frequencies in Hz to see how far apart they are in cents, plus the beat frequency you would hear if both tones sounded at once.
Cents measure pitch difference on a logarithmic scale (100 cents per semitone), calculated as 1200 × log₂(f2 ÷ f1). Beat frequency is simply the absolute difference between the two frequencies in Hz, the rate at which the combined sound pulses in volume when two close pitches ring together.
Frequency 1 (Hz):
Frequency 2 (Hz):
How It Works
Cents measure pitch difference on a logarithmic scale (100 cents per semitone), calculated as 1200 × log₂(f2 ÷ f1). Beat frequency is simply the absolute difference between the two frequencies in Hz, the rate at which the combined sound pulses in volume when two close pitches ring together.
How to Use This Tool
- Enter the first frequency in Hz.
- Enter the second frequency in Hz.
- Click Calculate to see the cents difference and beat frequency.
Beats are most noticeable when the two frequencies are close together (within a few Hz); as the gap grows, the beating becomes too fast to perceive as a pulse and instead sounds like a dissonant interval.
Did You Know?
- Piano tuners historically used beat frequencies by ear to tune octaves and fifths precisely, long before electronic tuners existed.
- A cent is defined as 1/100th of an equal-tempered semitone, so 1200 cents make up a full octave.
Frequently Asked Questions
Why do I hear a pulsing sound when two notes are close in pitch?
That pulsing is the beat frequency, caused by the two sound waves alternately reinforcing and canceling each other as their phases drift in and out of alignment.
What is considered “in tune”?
There is no universal cutoff, but many musicians aim for within about 5 cents of the target pitch for a note to sound acceptably in tune.