Uncertainty & measurement Calculators
From instrument readings to a defensible final result. Convert, combine and report measurement uncertainty.
Repeated measurements & timing
Calculate mean, range, half-range uncertainty and uncertainty per cycle, with an explicit instrument floor and comparison to SEM.
Open calculatorInstrument readings & zero error
Correct a zero offset and estimate reading uncertainty using a stated resolution convention or supplied instrument uncertainty.
Open calculatorAgreement within uncertainty
Compare two measurement intervals or a result with an accepted value. Check overlap and see the numerical gap with a careful conclusion.
Open calculatorPercentage uncertainty
Convert absolute uncertainty into percentage uncertainty. See the formula, substituted values and a correctly rounded measurement.
Open calculatorAbsolute uncertainty
Find absolute uncertainty from a measured value and percentage uncertainty, with full working and matched decimal-place rounding.
Open calculatorUncertainty propagation
Propagate uncertainties for sums, differences, products, quotients and powers using school-lab rules, with all working shown.
Open calculatorPercentage error & difference
Calculate percentage error against an accepted value or percentage difference between two values. Compare definitions and see the working.
Open calculatorSignificant figures
Round decimal or scientific-notation numbers to 1–15 significant figures. Understand leading zeros, trailing zeros and halfway rounding.
Open calculatorGradient uncertainty
Find gradient uncertainty from maximum and minimum acceptable slopes, plus percentage uncertainty and a rounded best-gradient result.
Open calculator