Statistics and math calculator
Root Mean Square Calculator
Calculate the root mean square, or quadratic mean, of one to 5,000 finite numeric values.
All input and results stay in this browser tab. This page uses no account, upload, remote calculation, URL state, analytics event, or persistent storage.
Enter values
Separate values with commas, spaces, or line breaks. Decimal and scientific notation are supported.
Loading local utility…
Result
Method
Uses RMS = √(Σx² ÷ n) with a scaled sum-of-squares algorithm to avoid intermediate overflow and underflow where JavaScript can still represent the final value.
Worked example
For 3 and 4, the mean square is (9 + 16) ÷ 2 = 12.5, so RMS = √12.5 ≈ 3.535533906.
Limitations
This calculates dataset RMS only. It does not calculate regression RMSE, sample a waveform, simulate a meter, perform spectral analysis, or process a live signal.
Related tool
Mean Calculator serves a different user job.