Math Calculators

Calculate percentages, find what percent one number is of another, and more.

Calculate percentage increase or decrease between two values.

Calculate your weighted and unweighted GPA from each course’s credits and grade.

Calculate the perfect tip amount.

Calculate sale prices instantly.

Work out the square footage of a room or area, and the cost to cover it at a price per square foot.

Estimate how much gravel an area needs at a given depth, in cubic yards, cubic feet and tonnes.

Find how many tiles and boxes an area needs, including the grout gap and a waste allowance.

Work out how much mulch an area needs, in cubic yards, cubic feet and the number of bags.

Calculate your course grade from assignment weights, and the score a final exam needs for your target.

Find the area of a rectangle, a triangle or a circle from its own measurements, in square metres, square feet and the unit you measured in.

Find the volume of a box, a cylinder or a sphere from its own measurements, in cubic metres, litres, cubic feet and US gallons.

Estimate concrete volume for slabs, rectangular columns and cylinders, then calculate bags from the stated package yield.

Find the surface area of a box, a closed cylinder or a sphere from its own measurements, in square metres, square feet and the unit you measured in.

Work out the standard deviation and the variance of a data set, with the population and the sample readings side by side.

Turn a sample mean, its standard deviation and the sample size into a 90, 95 or 99 percent confidence interval.

Turn a value, a mean and a standard deviation into a z-score, with the percentile and the tail probabilities beside it.

Find the percent error of a measurement against an accepted value, or the percent difference between two measurements.

Simplify a ratio to its lowest terms, solve the missing term of a proportion, or scale a ratio by a factor.

Find the density of a material from its mass and volume, or solve for the mass or the volume — with exact unit conversion and a sourced reference table of common substances.

Raise a number to any power, or take any root — the answers are exact whenever the mathematics is, and the eight exponent rules stand beside the result.

Find how much of a quantity is left after a time, how long it takes to fall to a target, or the half-life itself between two readings — the decay relation, stated and derived.

Evaluate a logarithm, find the base it was taken in, or undo it and recover the argument — exact where the mathematics is exact, with the six log rules beside the result.

Find the least common multiple or the greatest common divisor of a list of whole numbers, exactly, with every number’s prime factorisation and the Euclidean working beside the result.

Pick any two of voltage, current, resistance and power and the other two follow from V = I × R and P = V × I — exact where the numbers are exact, with the six relations beside the result.

Stack successive discounts on one price and see the final price, the saving and the effective single discount.

Draw random numbers from a range you set, with or without repeats, and repeat the same random draw with a seed.

Convert ordinary or scientific notation to normalized scientific notation and an expanded decimal, including zero and negative values.