Math tools

Math calculators

Solve percentage, ratio, probability, geometry, algebra, and everyday math problems.

Plan with clearer estimates

Math tools make common arithmetic and formula checks easier to audit. They are useful for quick estimates, homework checks, and everyday planning problems.

Write the formula first.
Check units and notation.
Round only at the end.

Percentage Calculator

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Percentage Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Ratio Calculator

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Ratio Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Scientific Calculator

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Scientific Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Fraction Calculator

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Fraction Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Slope Calculator

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Slope Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Probability Calculator

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Probability Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Average Calculator

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Average Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Median Calculator

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Median Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Standard Deviation Calculator

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Standard Deviation Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Area Calculator

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Area Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Volume Calculator

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Volume Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Circle Calculator

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Circle Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Triangle Calculator

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Triangle Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Pythagorean Theorem Calculator

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Pythagorean Theorem Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Quadratic Formula Calculator

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Quadratic Formula Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Exponent Calculator

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Exponent Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Logarithm Calculator

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Logarithm Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Modulo Calculator

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Modulo Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Permutation Calculator

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Permutation Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Combination Calculator

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Combination Calculator for quick math estimates with clear formulas, worked examples, and copyable results.

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Percentage Increase Calculator

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Calculate percentage increase between an original value and a higher new value with a clear formula and example.

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Percentage Decrease Calculator

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Calculate percentage decrease between an original value and a lower new value for prices, counts, and estimates.

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Percent of a Number Calculator

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Find what a percentage of a number equals, with copyable results and a simple worked example.

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Helpful math guides

Use these guides to understand the assumptions behind the calculators and check your estimate before acting on it.