Mathematics & Percentages
Arithmetic, percentages, fractions, statistics basics, number theory and number formats, computed exactly where possible.
- Basic Arithmetic CalculatorA safe online calculator for everyday arithmetic with + − × ÷, parentheses, percentages and square roots, following order of operations.
- Scientific CalculatorA scientific calculator with trigonometry in degrees or radians, logarithms, powers, roots, factorials, combinations and constants.
- Percentage of a Number CalculatorFind X percent of a number, or what percentage one number is of another.
- Percentage Change CalculatorCalculate the percentage change from an original value to a new value, with direction, absolute change and multiplier.
- Percentage Difference CalculatorCalculate the percentage difference between two values relative to their average — a symmetric comparison with no “original” value.
- Percentage Increase CalculatorIncrease a number by a percentage, optionally compounding the increase several times, and see the total change.
- Percentage Decrease CalculatorDecrease a number by a percentage, optionally repeatedly, and see the increase needed to get back to the start.
- Reverse Percentage CalculatorFind the original value before a percentage increase or decrease — for example the price before tax or before a discount.
- Percentage Point Difference CalculatorFind the difference between two percentages in percentage points and basis points, and the relative percent change.
- Fraction CalculatorAdd, subtract, multiply and divide fractions and mixed numbers with exact results in simplest form, mixed form and decimal.
- Fraction SimplifierReduce any fraction to lowest terms using the greatest common divisor, with mixed-number and decimal forms.
- Fraction to Decimal ConverterConvert a fraction to its exact decimal, detecting repeating digits and showing them in brackets.
- Decimal to Fraction ConverterConvert a decimal — including repeating decimals like 0.(3) — into an exact fraction, plus a best approximation with a limited denominator.
- Ratio CalculatorSimplify a ratio of two or more parts, express it as a unit ratio and split a total amount in that ratio.
- Proportion CalculatorSolve a proportion a/b = c/d for the missing value (the rule of three) by cross-multiplication.
- Average CalculatorCalculate the arithmetic mean of a list of numbers, with sum, count, minimum, maximum and range.
- Weighted Average CalculatorCalculate a weighted average of values and their weights, with the sum of weights and the unweighted mean for comparison.
- Median CalculatorFind the median, quartiles (Q1, Q3) and interquartile range of a data set, with the sorted values.
- Mode CalculatorFind the mode (most frequent value) of a data set, detect bimodal or multimodal data, and see a frequency table.
- Standard Deviation CalculatorCalculate sample or population standard deviation with the mean, coefficient of variation and standard error, using a numerically stable method.
- Variance CalculatorCalculate sample or population variance, the sum of squared deviations and the divisor used.
- Mean Absolute Deviation CalculatorCalculate the mean absolute deviation about the mean and the median absolute deviation about the median.
- Greatest Common Divisor (GCD) CalculatorFind the greatest common divisor (GCD/HCF) of two or more integers of any size, with Euclidean algorithm steps.
- Least Common Multiple (LCM) CalculatorFind the least common multiple (LCM) of two or more integers, exactly, even for very large numbers.
- Prime Number CheckerCheck whether a number up to 10^18 is prime, with its smallest factor and the next and previous primes.
- Prime Factorization CalculatorBreak a whole number up to 10^18 into its prime factors, with exponents, the number of divisors and their sum.
- Factorial CalculatorCalculate n! exactly for n up to 5000, with digit count, scientific notation and trailing zeros.
- Exponent CalculatorRaise a number to any power, including negative and fractional exponents, with exact integer results for whole-number powers.
- Square Root CalculatorCalculate square roots and simplify radicals, e.g. √72 = 6√2, and check whether a number is a perfect square.
- Cube Root CalculatorCalculate cube roots of positive and negative numbers and simplify radicals, e.g. ∛54 = 3∛2.
- Logarithm CalculatorCalculate logarithms to any base, plus natural (ln), common (log₁₀) and binary (log₂) logarithms.
- Scientific Notation ConverterConvert numbers to scientific, E and engineering notation with your chosen significant figures.
- Rounding CalculatorRound numbers to decimal places, significant figures or the nearest multiple, with half-up, banker’s rounding, floor, ceiling and more.
- Random Number GeneratorGenerate random whole numbers or decimals in a range, with or without repeats, using the browser’s cryptographically secure generator.
- Number Base ConverterConvert integers between any bases from 2 to 36 — binary, octal, decimal, hexadecimal and beyond — exactly, at any size.