Calculators›Math Calculators

Math Calculators

Percentages, fractions, averages and statistics.

Solve the three common percentage problems: percent of a number, what percent one number is of another, and percentage change.

Fraction Calculator

Add, subtract, multiply and divide fractions, with the answer simplified and shown as a decimal.

Standard Deviation Calculator

Calculate standard deviation, variance, mean and count for a set of numbers, for both samples and populations.

Average Calculator

Find the mean, median, mode and range of a list of numbers. Paste values separated by commas or spaces and see all four at once, with the count and sum.

Variance Calculator

Calculate sample and population variance from a list of numbers, with the mean, sum of squared deviations and both standard deviations shown alongside.

These cover the arithmetic that is easy to get wrong under time pressure. The percentage calculator handles the three questions people actually ask: what is X percent of Y, what percentage is X of Y, and what is the change between two numbers. Those are different sums, and mixing them up is the most common mistake in the category.

For sets of numbers, the average calculator gives mean, median and mode together, which matters because they answer different questions: the mean moves with outliers and the median does not. The standard deviation and variance calculators go a step further and measure how spread out the data is, in original units and squared units respectively.

The fraction calculator works in exact fractions rather than decimals, so a third stays a third instead of becoming 0.333. Each tool shows its working, which is the point if you are checking homework rather than just wanting the answer.