Percentage Calculator
Three percentage tools in one: X% of Y, X is what percent of Y, and percent change from one value to another.
Statistics Calculator
Enter a list of numbers — count, sum, mean, min, max, range, sample variance and standard deviation.
Quadratic Equation Solver
Solve ax² + bx + c = 0 — the discriminant, both roots (real or complex) and the vertex of the parabola.
Right Triangle Calculator
From two legs, or the hypotenuse and one leg: the third side, both angles in degrees, area and perimeter.
Ratio & Proportion Calculator
Three ratio tools: solve a : b = c : x for x, split a total in a given ratio, and simplify a ratio to lowest terms.
Fraction Calculator
Add, subtract, multiply or divide two fractions — the reduced fraction, the mixed number and the decimal.
Unit Converter
Convert length (in, ft, yd, mi, mm, cm, m, km), weight (oz, lb, g, kg) and temperature (°F, °C, K) in one place.
Probability Calculator
Permutations and combinations of n choose k, plus the chance of at least one success in N trials from a single-event probability.
Shape Area Calculator
Area and perimeter of a rectangle, triangle, circle, trapezoid or ellipse from its dimensions — pick the shape, enter the sizes.
Basic Geometric Volumes
5 geometric volume calculators with SVG diagrams