Fraction Calculator
Add, subtract, multiply and divide fractions, with the answer simplified and shown as a mixed number and decimal.
Math Tools
Equations, primes, fractions, statistics, logarithms and more — with the working shown.
Numbers and arithmetic
Ratio Calculator
Solve a proportion for the missing value, or simplify a ratio to its lowest terms.
GCD and LCM Calculator
Find the greatest common divisor and least common multiple of two or more numbers, with Euclid's steps.
Prime Number Checker
Check whether a number is prime and see its prime factorization, divisors and the nearest primes.
Significant Figures Calculator
Count the significant figures in a number and round it to any number of significant figures.
Scientific Notation Converter
Convert numbers to and from scientific, E and engineering notation, exactly.
Algebra and functions
Quadratic Equation Solver
Solve ax² + bx + c = 0 with real or complex roots, the discriminant and the vertex, with working.
Logarithm Calculator
Calculate logarithms in base 10, e, 2 or any base, with ln, log₁₀ and log₂ side by side.
Scientific Calculator
An online scientific calculator with trigonometry, logarithms, powers, roots, factorials and history.
Statistics and probability
Average Calculator
Find the mean, median, mode, sum and range of a list of numbers.
Standard Deviation Calculator
Calculate the standard deviation, variance and mean of a data set, for a sample or a population.
Permutation and Combination Calculator
Calculate nPr and nCr, with and without repetition, exactly — even for very large numbers.