Math Calculators
Everyday maths, done exactly and explained. These calculators cover percentages, fractions, averages, ratios, square roots, powers, rounding, the greatest common divisor, the least common multiple, prime numbers and a full scientific calculator.
Each page shows the formula with your own numbers, a worked example and the cases where a result can be misread, so you can check an answer instead of taking it on trust.
All 11 math calculators
- Percentage CalculatorPercent of a number, percentage change, increase and decrease
- Square Root CalculatorSquare roots to up to 20 decimals, with the simplified radical form
- Power CalculatorRaise any number to any power, with exact results for whole exponents
- Rounding CalculatorRound to decimals, significant figures or a multiple, with eight methods
- Average CalculatorMean, median, mode, range and standard deviation of a list of numbers
- Ratio CalculatorSimplify a ratio, find a missing value in a proportion, or split a total
- Fraction CalculatorAdd, subtract, multiply and divide fractions and mixed numbers
- Greatest Common Divisor CalculatorGCD of two to twenty whole numbers, with the Euclidean algorithm steps
- Least Common Multiple CalculatorLCM of two to twenty whole numbers, with prime factorisations
- Prime Number CheckerTest whether a number is prime and see its factors, divisors and neighbouring primes
- Scientific CalculatorExact arithmetic, trigonometry, logarithms, roots, powers and factorials
Exact results, and a mark when they are rounded
Most calculators and programs work on binary floating-point numbers, which is why 0.1 + 0.2 can come out as 0.30000000000000004. These calculators read what you type as an exact decimal and keep it exact, so 0.1 + 0.2 is 0.3 and one third times three is exactly one.
When an exact answer does not exist, for example the square root of 2 or the logarithm of 10, the result is calculated to many more digits than it is shown and is marked with ≈. The rounding method, such as rounding half away from zero or to the nearest even digit, is stated wherever it matters.