Measurement uncertainty calculator

How to use this calculator

Edit the measured values and their plus-minus uncertainties. The starter adds two values and combines independent uncertainties in quadrature.

Tap the math below to edit it and see the result. Once a result is ready, press Tab on a hardware keyboard to accept it. Outside a matrix, Return completes the line; the phone math keyboard has the same Return action.

Try it here

Interactive tools require JavaScript. You can read the guide and example without it.

What to know

The result is not interval arithmetic. Correlated errors need a covariance model; uncertainty display follows CE's significant-digit formatting.

Mathlean combines visual mathematical input with computation and canvas tools. Results depend on the expression and available engine support; check important answers independently.