Switch between frequency (Hz) and period (seconds). Zero or negative values are invalid.
For a positive value in the active mode, T = 1 ÷ f when converting from frequency (Hz) to period (seconds), and f = 1 ÷ T when converting from period to frequency. Division by zero is avoided by requiring a strictly positive input.
This calculator uses plain decimal numbers. If a result looks wrong, check whether you used a comma instead of a dot (or vice versa) where the field expects one.