Free Calculators
Free everyday calculators for the numbers that come up in daily life, work, and study. Use the percentage calculator to find a percent of a number, a percentage increase or decrease, or what percent one value is of another; work out an average (mean, median, and mode) from any list; split a restaurant bill with the tip calculator; or check a sale price with the discount and sales-tax calculators. Every calculator shows the exact formula it uses and at least three worked examples, so you can verify the result by hand instead of taking it on faith. All of them run instantly in your browser with no sign-up, and link through to related finance, health, and converter tools when you need the next step.
Enter your numbers in the fields — add as many as you need, or paste a whole list — to get the mean (average), median, mode, range, sum, and count at once.
A fast, free online calculator for everyday arithmetic. Type an expression or tap the buttons — it respects the order of operations and parentheses.
Work out percentages three ways: a percent of a number, what percent one value is of another, and the percentage change between two numbers.
Relate volume (m³) to area (m²) using a depth or thickness. Enter any two of volume, area, and depth and the calculator finds the third — handy for concrete, flooring, soil, and paint coverage.
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Frequently asked questions
Are these calculators free to use?
Yes. Every calculator on HIFreeTools is completely free, needs no sign-up, and runs in your browser.
Do the calculators show the formula?
Yes — each calculator shows the exact formula it uses plus worked examples, so you can verify the result by hand instead of trusting a black box.
Which tool finds a percentage of a number?
Use the Percentage Calculator. It handles "X% of Y", percentage increase or decrease, and "what percent is X of Y" in one place.