📡 Signal-to-Noise Ratio Calculator
Calculate the signal-to-noise ratio (SNR) in decibels from signal and noise power (or voltage) levels.
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What SNR measures
Signal-to-noise ratio (SNR) compares the level of a desired signal to the level of background noise. A higher SNR means a cleaner, more distinguishable signal, and it’s a key metric in audio, electronics, imaging, and communications.
The formula
For power quantities, SNR (dB) = 10 × log₁₀(Psignal / Pnoise). For amplitude/voltage quantities, SNR (dB) = 20 × log₁₀(Asignal / Anoise), since power is proportional to amplitude squared.
These are the standard decibel formulas used throughout electrical engineering and signal processing.
Last reviewed August 2026