OnlineFreeToolBoxCalculators
Percentage Calculator
What is X% of Y?
Example: 20% of 150
X is what percent of Y?
Example: 30 is what percent of 150
Percentage increase / decrease
Example: change from 150 to 180
About Percentage Calculator
The Percentage Calculator answers the three most common percentage questions: what is a given percentage of a number (20% of 150 is 30), what percent one number is of another (30 is 20% of 150), and the percentage increase or decrease between two values (from 150 to 180 is +20%). That covers discounts, tips, tax estimates, mark-ups, grades and many everyday money questions.
Percentages appear everywhere, yet working them out mentally is slow and error-prone, especially with uneven numbers. This calculator gives a clean, exact result so you can check a price, a bill or a score without reaching for a spreadsheet.
How to use Percentage Calculator
- Pick the question you need: “What is X% of Y?”, “X is what percent of Y?”, or “Percentage increase / decrease”.
- Enter your numbers — the result updates live as you type, with no button to press.
- Read the result in the dark panel under that section.
Why use Percentage Calculator
It is deliberately simple: one question, one clear answer, with no sign-up and no spreadsheet to open.
- Instant answers — no formula to remember or type.
- Useful for shopping and bills — check a discount or a share of a total in seconds.
- Good for study — check homework answers and see the arithmetic behind a percentage.
Common uses
Common uses include finding a percentage of a price before a sale, working out a tax amount on a bill, calculating a share of a monthly budget, and checking how much of a savings goal has been reached. Students use it for marks and grades, shoppers for quick price checks, and small businesses for working out commission amounts.
Your privacy
The numbers you enter are processed in your browser only and are never uploaded or stored.
Honest limits
This page calculates a percentage of a number. It does not offer separate modes for “what percentage is one number of another” or for percentage change between two values.
Frequently asked questions
How is percentage change calculated?
Change divided by the original number, multiplied by 100.
What does 20% of 150 mean?
It means 20 parts out of every 100 parts of 150, which is 30. Enter 150 as the number and 20 as the percentage to see it.
Can I use decimals?
Yes. You can enter decimal numbers and percentages, and the result is shown with decimal places.
What if I need a percentage change instead?
This page calculates a percentage of a number. For a change between two values, work out the difference first and then express it as a percentage of the original value.
Is the result rounded?
The result is shown to two decimal places, which is enough for most money and mark calculations.