Root Mean Square

How to use this calculator

1. Enter first value in number.
2. Enter second value in number.
3. Enter third value in number.
4. Select Calculate and keep the output unit with the answer.

Before you use the answer

Choose the reference quantity before interpreting the number. A ratio, a percentage and a percentage-point difference may use the same observations while answering different questions. For recorded data, keep the original values beside the summary so an unexpected result can be traced back to its inputs.

RMS is not the same as the standard deviation unless the mean is zero under the same population convention.

Does it save my inputs?

No calculation history is stored by this website. The calculator works locally in your browser. See the privacy policy for hosting and contact details.

Why might a result be approximate?

Measurement uncertainty, ideal-model assumptions and floating-point rounding can all matter. Displaying more digits does not improve the original measurement.