basic

Signal-to-Noise Ratio (SNR) in Decibels Calculator

SNR = 10·log₁₀(P_signal / P_noise) dB.

Calculates SNR in dB from signal and noise power levels: SNR_dB = 10·log₁₀(P_s/P_n). Converts between linear SNR and dB. SNR > 40 dB is generally considered excellent.

Daniel Oh By Daniel Oh
Published Last reviewed 1 min read

Inputs

mW
mW

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

SNR_dB = 10·log₁₀(P_s / P_n)

In depth

Calculates SNR in dB from signal and noise power levels: SNR_dB = 10·log₁₀(P_s/P_n). Converts between linear SNR and dB. SNR > 40 dB is generally considered excellent.