Sample at least twice the fastest signal

To capture a signal faithfully, sample above 2× its highest frequency — in practice 5–10×.

Why it works

The Nyquist–Shannon limit is a hard floor, not a target: real systems need margin for filters, noise and phase.

Do it exactly

Estimate with the rule, then check it against the calculator that models it properly.

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What sample rate do you need?

To capture a signal faithfully, sample above 2× its highest frequency — in practice 5–10×. The Nyquist–Shannon limit is a hard floor, not a target: real systems need margin for filters, noise and phase.

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