SNR Calculator
Calculate the signal-to-noise ratio in decibels from signal and noise power or voltage levels.
mW
mW
SNR
30.0 dB
SNR (linear)1,000.0
Noise as % of Signal0.100 %
SNR vs Signal Power
Signal-to-Noise Ratio
SNR compares the level of a desired signal to the background noise level. Higher SNR means a cleaner signal.
Formula
SNR (dB) = 10 x log10(P_signal / P_noise)
For voltage measurements: SNR (dB) = 20 x log10(V_signal / V_noise)
Reference Points
Example Calculation
Signal power of 100 mW with noise power of 0.1 mW.
- 01SNR linear: 100 / 0.1 = 1000
- 02SNR dB: 10 x log10(1000) = 30.0 dB
- 03Noise fraction: 0.1 / 100 x 100 = 0.1%
Frequently Asked Questions
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