Percentages show up everywhere: in tips, discounts, price increases, grades and statistics. The math calculators help you find X% of a number, what percentage one number is of another, the percent increase or decrease between two values, and the final price after one or more stacked discounts.
Each page explains the formula step by step, shows worked examples and points out common mistakes, such as why adding and then subtracting the same percentage does not bring you back to the starting value. There is also a scientific calculator, plus calculators for fractions, averages and standard deviation, grades, probability, the Pythagorean theorem and the circumference and area of a circle.
All calculators in this category
- Scientific calculator – Online calculator with exponents, roots, trig functions, logarithms and factorials.
- Standard deviation – Standard deviation and variance of a list of numbers, step by step.
- Fractions – Calculate with fractions and get a simplified answer.
- Grade calculator – Your weighted grade and the score you need on the next test.
- Average – Mean, median, mode and spread of a list of numbers.
- Circle calculator – Area, circumference, radius and diameter of a circle.
- Probability – Calculate probabilities, the chance of at least once, and combinations.
- Pythagorean theorem – Find the missing side of a right triangle.
- Percentage calculator – X% of a number, X as a percent of Y, and adding or subtracting a percentage.
- Percentage change – Percent increase or decrease between two values, and how to get back.
- Discount calculator – Sale price after a discount, stacked discounts and percent off.
Looking for something else? See all calculators on the home page.