Three common percentage problems in one tool: find a percentage of a number, find what percent one number is of another, or find the percent change between two numbers.
15% of 200 is 30.
To find X% of a number, convert the percentage to a decimal by dividing by 100, then multiply: 15% of 200 is (15 ÷ 100) × 200 = 30.
To find what percent one number is of another, divide the part by the whole and multiply by 100: 30 out of 200 is (30 ÷ 200) × 100 = 15%.
To find percent change between two values, subtract the original from the new value, divide by the original, and multiply by 100. A positive result is an increase; a negative result is a decrease.
What's the difference between percentage points and percent change?
If a rate moves from 20% to 25%, that's a 5 percentage point increase, but a 25% relative increase in the rate itself. This calculator's "% change" mode gives the relative change.
Can I use negative numbers?
Yes, the percent change calculation works with negative starting or ending values, though results can be harder to interpret in those cases.