Significant Figures Calculator

Count sig figs, do sig-fig-correct arithmetic, and propagate measurement uncertainties

Count significant figures
4
significant figures

Rules: non-zero digits count; leading zeros don't; zeros between digits do; trailing zeros count only with a decimal point (1200 → 2 sig figs, 1200. or 1.200×10³ → 4).

Sig-fig arithmetic & uncertainty propagation
Raw result14.532
Sig-fig rounded15
Multiplication/division: round to the fewest significant figures (2).

With uncertainty14.532 ± 1.21
Relative uncertainty8.34%

Sig figs and error propagation

Every measured value carries limited precision, and lab reports are marked on handling it correctly. This tool applies the standard rules — fewest decimal places for addition/subtraction, fewest significant figures for multiplication/division — and propagates independent uncertainties in quadrature: absolute uncertainties add for sums, relative uncertainties add for products. Essential for chemistry and physics lab work.

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