Math
Math tools: random numbers, GCD/LCM, prime checker, factorial, percentages, base converter and body mass index.
Tools — Math
Percentage calculator
Calculate what percentage one number is of another.
Random number generator
Generate random numbers within a range, instantly and locally.
GCD and LCM calculator
Find the GCD and LCM of two or more numbers instantly.
Prime number checker
Check if a number is prime and see its prime factors.
Factorial calculator
Calculate the factorial (n!) of a number, exact for large values.
Binary / decimal / hex converter
Convert numbers between binary, decimal, hexadecimal and octal.
Scientific calculator
Scientific calculator: trigonometry, logarithms, roots, powers, π and e. Type the expression and get the result.
Rule of three calculator
Solve direct and inverse proportions instantly. Enter three values and get the fourth.
Dice roller
Roll dice online: choose how many dice and how many faces (d4, d6, d8, d10, d12, d20, d100).
Flower petal calculator
Find the typical number of petals of common flowers and see how petal counts follow the Fibonacci sequence.
Statistics calculator
Calculate mean, median, mode, range and standard deviation from a list of numbers. Free and instant.
Fraction calculator
Add, subtract, multiply or divide two fractions and get the simplified result plus the decimal. Free and instant.
Logarithm calculator
Calculate the logarithm of a number in any base, plus natural log (ln), log base 10 and log base 2. Free.
Exponent calculator
Raise any base to any power (bⁿ), including negative and decimal exponents. Free, instant, in your browser.
Fibonacci calculator
Generate the Fibonacci sequence up to N terms and see the sum. Big-integer accurate. Free and instant.
Quadratic equation calculator
Solve ax² + bx + c = 0 for real or complex roots, with the discriminant. Free, instant, in your browser.
Probability calculator
Calculate the probability of an event from favourable and total outcomes, as a percentage and decimal. Free.
Scientific notation converter
Convert any number to scientific notation (a × 10ⁿ) and E-notation. Free, instant, in your browser.
Modulo calculator
Calculate a mod b — the remainder and quotient of a division. Free, instant, in your browser.
Matrix determinant calculator
Calculate the determinant of a 2×2 or 3×3 matrix. Free, instant, in your browser.
Percentage change calculator
Calculate the percentage increase or decrease from one value to another. Free, instant, in your browser.