EVM to SNR Converter
Enter the known values and run the calculation.
Overview
Translate modulation quality into approximate SNR terms for mixed RF and digital signal work.
This converter maps RMS EVM into an approximate SNR number so a modulation-quality result can be interpreted in more familiar signal-quality terms.
Use it when a transmitter or vector analyzer reports EVM and the next discussion is in SNR.
The math and how it's used
The approximation uses SNR(dB) = -20 log10(EVM linear) when EVM is expressed as an RMS ratio.
The tool also returns EVM in percent, linear ratio, and dB so the reading can be translated back into the format used on the bench.
This is a shorthand conversion between EVM and SNR when modulation quality is being summarized from a communications measurement.
It is best treated as an estimate tied to the usual small-error relationship. Phase noise, nonlinearity, and carrier leakage can all make the real interpretation more nuanced.
Limits of the result
EVM is affected by more than additive noise. Phase noise, distortion, IQ imbalance, and compression can all move the result.
That means the SNR output here is a useful approximation, not a replacement for the actual modulation error breakdown.