Percentage Calculator

Find what percentage one number is of another in a single step.

Frequently Asked Questions

Clear, evidence-informed answers about daily hydration.

How do you calculate a percentage?

Divide the part by the whole, then multiply the answer by 100. For example, 25 divided by 200 equals 0.125, or 12.5%.

What if the whole is zero?

A percentage cannot be calculated when the whole is zero because division by zero is undefined.