Mathematics

Calculate how much paint you need for a room or wall. Find out if your paint is enough, or how many cans to buy. Free online paint calculator.

Percentage Calculator online: calculate percentages, discounts, ratios and percentage change in seconds. Fast, free and easy to use on NtoolBox.

Area Calculator online: calculate rectangle, triangle, circle and trapezoid areas from dimensions. Fast, free and easy to use on NtoolBox.

Volume Calculator online: calculate cube, sphere, cylinder and cone volumes from dimensions. Fast, free and easy to use on NtoolBox.

Average Calculator online: calculate mean, median, mode, sum and count from a number list. Fast, free and easy to use on NtoolBox.

Age and Date of Birth Calculator online: calculate age from date of birth and show years, months and days. Fast, free and easy to use on NtoolBox.

Calculate the exact number of days, weeks, months and years between any two dates. Free, instant, runs in your browser — no sign-up needed.

Calculate how many tiles you need for any room. Enter area, tile size and waste factor — instant result. Free online tile calculator.

Solve ratio and proportion problems instantly. Find the unknown in A:B=C:D, simplify ratios. Free online ratio calculator.