Percentage Calculator
This calculates three common percentage problems: what X% of a number is, what percentage one number is of another, and the percentage change between two values. Enter any two known values and it works out the third instantly.
How it works
- Pick the calculation type — percentage of a value, percentage change, or what percentage one number is of another.
- Enter the numbers in the fields provided.
- The result appears instantly with a plain-language summary so it is easy to share or explain.
Frequently asked questions
How do I calculate a percentage increase or decrease?
Percentage change is (new value minus old value) divided by old value, times 100. A positive result is an increase, a negative result is a decrease — this calculator does that division for you automatically.
How do I find what percentage one number is of another?
Divide the part by the whole and multiply by 100 — for example, 30 out of 120 is (30 / 120) x 100 = 25%.