Percentage Calculator

Calculate percentages with multiple modes: percent of, what percent, percent change, and increase/decrease.

15% of 200 =
30
(15 / 100) × 200 = 30

Frequently Asked Questions

There are four modes: "X% of Y" calculates a percentage of a number, "X is what % of Y?" finds what percentage one number is of another, "% change from X to Y" calculates percent change between two values, and "% increase/decrease" applies a percentage to increase or decrease a value.
Percentage change is calculated as ((New Value - Old Value) / |Old Value|) × 100. A positive result means an increase, while a negative result means a decrease. For example, going from 80 to 100 is a 25% increase.
Percentage change calculates the difference between two known values. Percentage increase/decrease starts with a value and a percentage, then calculates the new value. For example, "200 increased by 15%" gives 230.
Yes, all inputs accept decimal numbers. You can enter values like 15.5, 200.75, or 0.5 for precise calculations.
Results are displayed with up to 6 decimal places for precision, but trailing zeros are removed for cleanliness. Very large or very small numbers are handled accurately.