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Percentage RSD Calculator

%RSD = standard deviation ÷ mean × 100

Method / formula%RSD = standard deviation ÷ mean × 100

Keep units consistent. Record assumptions and independently verify critical results.

INPUT DATA

Enter calculation values

Select the unit for each measurement. Compatible values are converted automatically before calculation.

CALCULATED RESULT—

The result updates as valid values are entered.

Unit handlingCompatible units are normalized internally. Confirm units, assumptions and significant figures before use.

CALCULATION GUIDE

Understand your calculation

Clear inputs, a practical example and the context you need to interpret your result.

How it works

Computes the arithmetic mean and sample standard deviation s = sqrt(sum((x − mean)²)/(n − 1)); %RSD = 100 × s/|mean|.

Inputs and units

Enter at least two finite numbers separated by commas, all on one measurement basis. Do not use thousands separators, empty entries or text. The selected unit cancels in the ratio.

Worked example

For 98, 100, 102: mean = 100; squared deviations sum = 8; s = sqrt(8/2) = 2; RSD = 2/100 × 100 = 2.000%.

Interpreting the result

Lower RSD indicates smaller relative spread for comparable measurements. Identical nonzero values yield 0.000%.

Assumptions and limitations

This uses sample, not population, standard deviation. Zero mean is undefined; near-zero means make RSD unstable. Negative means use absolute magnitude but may lack useful relative interpretation. No acceptance limit or outlier removal is applied.