📐 Math Tools

Free calculators for math — percentages, fractions, geometry, algebra, and everyday number crunching.

Enter radius, diameter, area, or circumference — instantly get all other circle measurements with step-by-step formulas

Calculate the volume of any cylinder — pipes, tanks, barrels, cans. Enter diameter and height, get volume in liters, gallons, cubic meters, and more.

Calculate any percentage — what is X% of Y, X is what % of Y, increase by %, discount, and percentage change between two numbers