Signal-to-Noise Ratio (SNR) Calculator
Work out signal-to-noise ratio in decibels from two levels, from a voltage/amplitude or power ratio, or convert between SNR and the effective number of bits (ENOB).
SNR is how far your wanted signal sits above the noise — higher is cleaner. These are standard formulas; it’s a calculator, not a measurement.
SNR from two levels
SNR (dB) = signal level − noise level. Use any consistent dB scale (e.g. both in dBFS).
SNR from amplitude or power
Amplitude (voltage): SNR = 20·log₁₀(signal/noise). Power: SNR = 10·log₁₀(signal/noise). Pick which your numbers are.
SNR ↔ effective number of bits
For an ideal converter: SNR = 6.02·N + 1.76 dB, so ENOB = (SNR − 1.76) / 6.02. Edit either field.
Ideal SNR by bit depth
Theoretical best SNR of a perfect N-bit converter (6.02·N + 1.76 dB).
How SNR Works
Signal-to-noise ratio compares the level of the signal you want to the background noise you don’t, expressed in decibels. From two measured levels it’s simply the difference: a signal at −12 dBFS over a −72 dBFS noise floor gives 60 dB SNR. From raw amplitudes (voltages) it’s 20·log₁₀(signal/noise); from powers it’s 10·log₁₀(signal/noise), because power goes as amplitude squared.
For digital systems, the theoretical SNR of an ideal converter is 6.02·N + 1.76 dB for N bits — about 98 dB for 16-bit and 146 dB for 24-bit. The effective number of bits (ENOB) works backwards from a measured SNR to say how many real bits of resolution you’re getting once noise and distortion are included.