math calculators
Math calculators
Tools to solve percentage, proportion, age, and day counts without doing the math by hand. Enter your values and see instant results, with no sign-up required and no ads hiding your answer.
All tools
Percentage calculator
Calculate percentages, proportions, and variations.
½Fraction calculator
Simplify, add, subtract, multiply, or divide fractions.
ΣProbability calculator
Calculate simple, combined (AND/OR), and repeated-trial probability.
ΣStandard deviation calculator
Calculate standard deviation, variance, and coefficient of variation.
ΣScientific calculator
Trigonometry, logarithms, powers, roots, and memory.
√Square root calculator
Calculate square roots, simplified radicals, and perfect squares.
xⁿExponent calculator
Calculate powers and convert to scientific notation.
ΣLogarithm calculator
Logarithm in any base, comparison, and pH calculation.
ΣAge calculator
Exact age in years, months, and days.
ΣRule of three
Find proportions automatically.
ΣDays between two dates
Days, weeks, months, and business days between dates.
x̄Average calculator
Calculate simple average, weighted average, and the grade you still need.
x̄Weighted average calculator
Weighted average with the relative weight of each item.
ΣLCM calculator
Least common multiple of two or more numbers.
ΣGCD calculator
Greatest common divisor of two or more numbers.
ΣPrime number calculator
Check if a number is prime, see its factorization, and list primes up to a limit.
ΣFactorial calculator
Exact factorial of large numbers, with guaranteed precision.
ΣRatio calculator
Simplify ratios and split values according to a ratio.
ΣProportion calculator
Check proportions and find the missing term.
x̄Mean, median, mode calculator
Calculate the three measures of central tendency, plus a statistical summary.
ΣVariance calculator
Step-by-step variance and pooled variance of two groups.
ΣPermutation calculator
Permutations (nPr), combinations (nCr), and permutations with repetition.
ΣCombination calculator
Combinations (nCr), combinations with repetition, and lottery odds.
ΣGeometry calculator
Area, perimeter, volume, and surface area of shapes and solids.
ΣTriangle calculator
Angles, sides, area, and type from any three triangle measurements.
ΣPythagorean theorem calculator
Hypotenuse, missing leg, right triangle check, and distance between points.
½Fraction to decimal converter
Fraction to decimal, decimal to fraction, and repeating decimal to fraction.
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Frequently Asked Questions
How do you calculate a percentage of a value?
Simply multiply the value by the desired percentage and divide by 100. Our calculator also works in reverse: calculating what percentage one number is of another, or the percentage change between two values.
What is the rule of three?
It is a mathematical method to find an unknown value based on a proportion between known quantities. It can be simple (involving two quantities) or compound (involving three or more related quantities).
Does the days between dates calculator count business days?
Yes, in addition to total calendar days, it also displays the count in weeks, months, and business days between the two selected dates.