Percentage Calculator
Four calculators in one: find a percentage of a number, work out what percentage one number is of another, calculate the percentage increase or decrease between two numbers, or find the result of applying a percentage change.
Percentage Calculator
Four calculators in one: find a percentage of a number, work out what percentage one number is of another, calculate the percentage increase or decrease between two numbers, or find the result of applying a percentage change.
How Percentage Calculator Works
The calculator covers four of the most common percentage questions, each with its own formula:
Switch between the four modes at the top of the calculator — the input labels and the formula shown update automatically to match whichever one you pick.
Worked Example
Mode: X% of Y — What is 20% of 500? → (20 ÷ 100) × 500 = 100
Mode: % change — A product's price moved from $80 to $92. Change = ((92 − 80) ÷ 80) × 100 = +15%
Both calculations run instantly in the calculator above — just switch the mode toggle to match the question you're asking.
Frequently Asked Questions
What percentage calculations does this tool support?
Four: finding X% of a number, finding what percentage one number is of another, finding the percentage increase or decrease between two numbers, and finding the result after applying a percentage change to a number.
How do I calculate a percentage increase or decrease?
Switch to the "% change, X → Y" mode, enter the original value as X and the new value as Y — the calculator returns the percentage change, shown as a positive number for an increase or negative for a decrease.
What's the difference between 'percentage increase' and 'percentage of'?
"X% of Y" finds a portion of a number (e.g. 20% of 500 = 100). "Percentage increase/decrease" compares two numbers to find how much one differs from the other as a percentage — a completely different calculation that people often mix up.