Math

Percentage Calculator The three classic percentage problems solved instantly: X% of Y, X is what % of Y, and % change. Rule of Three Calculator Solve direct and inverse proportions: enter three known values and get the fourth, with the math spelled out. Number Base Converter Convert numbers between binary, octal, decimal and hexadecimal — all four fields update as you type. Weighted Average Calculator Average values that carry different weights — and find the grade you need on the next test. LCM & GCD Calculator Find the least common multiple and the greatest common divisor of any list of whole numbers, step by step. Simple Interest Calculator Calculate simple interest and the final amount — or leave one field empty to find the principal, rate or time. Discount Calculator Work out the price after a discount, the percentage between two prices, and what stacked discounts really add up to. Factorial, Permutation & Combination Calculator Work out n!, arrangements, combinations and anagram counts exactly, with every step shown in your browser. Fraction Calculator & Simplifier Reduce any fraction to lowest terms and add, subtract, multiply or divide two fractions — with the GCD and the LCM shown. Fraction ↔ Decimal Converter Turn a fraction into a decimal — repeating period included — and any decimal back into an exact fraction. Scientific Notation Converter Convert any number to scientific and engineering notation, and back again, with significant figures counted. Prime Number Checker & Factorizer Check whether a number is prime, break it into prime factors, list every prime up to N and find the next one. Pythagorean Theorem Calculator Find the hypotenuse or a missing leg of a right triangle, with every step of the calculation shown. Area & Perimeter Calculator Area and perimeter of squares, rectangles, triangles, circles, trapezoids and rhombuses, with the formula applied to your numbers. Volume Calculator Volume of cubes, boxes, spheres, cylinders, cones and pyramids — plus surface area where it is direct — in your browser. Angle Converter Convert degrees, radians, gradians and degrees-minutes-seconds, with the sine, cosine and tangent of the angle. Multiplication Table Times table for any number from 1 to 100, a clickable 1-10 grid and a practice mode with a session score. Molar Mass Calculator Type a chemical formula and get the molar mass in g/mol, with the contribution of each element — using IUPAC 2021 atomic weights. Compound Interest Calculator Calculate compound interest with monthly contributions — see how your money grows over time. Quadratic Equation Solver Solve ax² + bx + c = 0 — see the discriminant, the roots and whether they are real or complex. Matrix Calculator Compute the determinant, transpose or inverse of a matrix up to 10×10 — with step-by-step results. Function Plotter Type a mathematical function and see its graph plotted on an interactive canvas with axes and grid. Average Speed Calculator Calculate speed, distance or time from any two of the three — type two and the third is computed. Free Fall Calculator Calculate how long an object takes to fall from a given height, or how far it falls in a given time — with final velocity. Kinetic & Potential Energy Calculator Calculate kinetic energy from mass and velocity, potential energy from mass and height, or both at once. Dilution Calculator (C₁V₁ = C₂V₂) Solve the dilution equation for any unknown — concentration or volume — in one step. pH Calculator Enter pH, pOH, [H⁺] or [OH⁻] and see the other three instantly — at 25 °C.