Calculate the Signal-to-Noise Ratio (SNR) in decibels (dB) for power or voltage measurements.
Last updated: March 2026 | By ForgeCalc Engineering
Signal-to-Noise Ratio (SNR) is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. It is defined as the ratio of signal power to the noise power, often expressed in decibels (dB).
A higher SNR indicates a clearer signal with less background interference. In audio, a high SNR means cleaner sound; in imaging, it means less graininess; and in data transmission, it means fewer errors.
P_s = Signal Power, P_n = Noise Power
V_s = Signal Voltage, V_n = Noise Voltage
It depends on the application. For high-quality audio, 90dB+ is excellent. For digital communications, 10-20dB might be sufficient for reliable data transfer.
Yes. A negative SNR (in dB) means the noise level is higher than the signal level. This is common in advanced signal processing where signals are 'buried' in noise.
SNR only compares signal to noise. SINAD (Signal-to-Noise and Distortion) also includes the power of harmonic distortion in the denominator, providing a more complete measure of signal quality.
Generally, increasing the bandwidth of a system increases the total noise power (as noise is often spread across frequencies), which can lower the SNR.
Related Tools
Calculate acoustic impedance.
Calculate signal attenuation.
Calculate beat frequency.
Calculate Bragg's Law.
Calculate critical damping.
Calculate damping ratio.