Math Tools
Quick answers to everyday maths.
Percentage Calculator Three percentage calculators in one — find a percentage of a number, a ratio as a percentage, and percentage change. Prime Number Checker Test any whole number for primality and, if it is composite, see its prime factors. Average Calculator Calculate the mean, median, mode, range, sum and count of any list of numbers. Fraction Calculator Enter two fractions and an operation to get a simplified result, with decimal and mixed-number forms. GCD & LCM Calculator Enter a list of whole numbers to get their GCD and LCM at once. Quadratic Equation Solver Enter the coefficients a, b and c to find the roots, discriminant and vertex of a quadratic equation. Roman Numeral Converter Type a number to get its Roman numeral, or type a numeral to get the number — both directions update live. Ratio Calculator Enter a ratio to simplify it, see it as a decimal, and scale it so the first term equals any number. Circle Calculator Enter any one circle measurement — radius, diameter, circumference or area — to get all the others. Triangle Calculator Enter the three side lengths to get area, perimeter, all three angles and the triangle's type. Scientific Notation Converter Enter a number in any form to see its scientific, engineering, E-notation and decimal equivalents. Factorial Calculator Calculate the exact factorial of any whole number up to 5000, with the full number of digits. Modulo Calculator Find a mod n with the quotient, the programming remainder and the true mathematical modulo. Logarithm Calculator Calculate a logarithm in any base, plus natural (ln), common (log₁₀) and binary (log₂) logs. Significant Figures Calculator Round a number to a set number of significant figures, and count the sig figs in any value. Number to Words Convert any number into written words, handling negatives and decimals, in your page language.