Free Online Calculators
Finance, math, health, construction, and everyday tools in one searchable catalog.
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Random Number Generator — One Number or a Unique Sample
Ratio Calculator
Sample Size Calculator
Standard Deviation Calculator
Triangle Calculator
Calculator descriptions
Random Number Generator — One Number or a Unique Sample
Generate one number from a clearly labelled inclusive range, or create, sort, copy and download a larger random sample.
Ratio Calculator
Simplify ratios, scale quantities, split a total and solve proportions exactly. Fractions, editable examples and clear visual comparisons.
Sample Size Calculator
Plan completed survey responses, expected invitations and sampling precision. Explore the trade-off between sample size and margin of error.
Standard Deviation Calculator
Calculate sample or population standard deviation from a list or frequency table. Explore real data points, their distances and contributions to spread.
Triangle Calculator
Solve a triangle from three known measurements. See all sides, angles, area and heights, and compare both possible SSA shapes on one scale.
