What this calculator does
Beat frequency works out how fast two close sound frequencies pulse in and out of phase. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
Formulaf_beat = |f1 − f2|; T_beat = 1/f_beat
The inputs explained
| Field | What to enter |
|---|---|
| Frequency 1 (Hz) | A number, measured in Hz. Starts at 440. |
| Frequency 2 (Hz) | A number, measured in Hz. Starts at 445. |
Worked examples
Every figure in the tables below is produced by this page’s own calculator at build time, so the numbers and the tool always agree. Select any row to load that scenario.
How the answer changes with frequency 1
Every other input is held at the calculator’s starting values while frequency 1 varies. Select any row to load that scenario into the calculator.