Binaural beat calculator
Two directions: from a carrier and a beat to the two tones, or from two tones back to the beat they produce. The arithmetic is simple; the confusion around it is not.
A binaural beat is the difference between the two tones. 200 Hz in the left ear and 210 Hz in the right produce a 10 Hz beat over a 200 Hz carrier. Neither ear receives a 10 Hz sound — that rate is below hearing, and the beat exists only when the two signals are compared.
Why this needs a calculator at all
Because two numbers get called "the frequency" and people mean different ones. A track labelled "10 Hz" contains no 10 Hz sound; it contains two audible tones ten hertz apart. A track labelled "432 Hz" is usually a carrier with no beat at all. Once you can convert between the two, most of the confusing writing in this field becomes readable.
Worked examples
| You want | Set | Ears receive |
|---|---|---|
| A 4 Hz delta beat for sleep | Carrier 100, beat 4 | 100 Hz and 104 Hz |
| A 10 Hz alpha beat | Carrier 200, beat 10 | 200 Hz and 210 Hz |
| A 40 Hz gamma beat | Carrier 300, beat 40 | 300 Hz and 340 Hz |
| 432 Hz against concert pitch | Left 432, right 440 | An 8 Hz alpha beat |
| No beat at all | Both ears the same | A pure tone |
The fourth row is worth noticing: the gap between the two tuning standards is itself an alpha-rate beat, which is why playing 432 and 440 Hz together sounds like a slow sway rather than a clash.
Choosing a carrier
- 100–500 Hz — beats are clearest here; the calculator warns outside this range.
- Below 100 Hz — earbuds reproduce it poorly and the beat gets muddy.
- Above 500 Hz — the beat becomes progressively harder to perceive, and a shrill carrier is tiring long before it stops working.
- Above roughly 40 Hz of beat — the difference stops being a beat and becomes roughness, then a third pitch. That is a hearing phenomenon, not a limit of the tool.
Now hear it
Questions
How do you calculate a binaural beat?
Subtract the two frequencies. The beat is the difference; the lower of the two is usually called the carrier.
What frequencies make a 10 Hz beat?
Any pair ten hertz apart — 200 and 210, 150 and 160, 440 and 450. The carrier changes the pitch you hear, not the beat.
Is there a maximum beat frequency?
Perceptually, yes. Past about 30–40 Hz the difference is heard as roughness rather than a beat, and further up it becomes a separate pitch.
Does the carrier affect the effect?
It affects how clearly you perceive the beat. No evidence supports one carrier producing a different outcome than another.
Running this on a phone? The Brainwave Generator app keeps playing with the screen off, works without a connection, and carries the same engine. Free on iOS and Android.