Percentage Calculator
Answer the three percentage questions people actually ask: what is X% of Y, X is what percent of Y, and X is Y% of what. Pick the question, enter the two numbers you know, and the answer appears with the full sentence written out.
- In words
- 15% of 80 is 12
Saved setups
Save a set of inputs you reuse — your usual rate, your loan, your room sizes — and load it back in one tap.
Your recent calculations
Results you calculate here are kept on this device so you can come back to them.
Formula
How to use it
- Choose the question that matches your problem.
- Enter the two numbers you know — the calculator only shows the fields that question needs.
- Read the answer and check the sentence underneath to make sure it says what you meant.
Worked examples
What is 15% of 80?
- Answer
- 12
- In words
- 15% of 80 is 12
45 is what percent of 60?
- Answer
- 75
- In words
- 45 is 75% of 60
30 is 25% of what number?
- Answer
- 120
- In words
- 30 is 25% of 120
Mental shortcuts
To find 10% of a number, move the decimal point one place left: 10% of 80 is 8. Then 5% is half of that (4), 1% is the decimal point moved two places (0.8), and 15% is 10% plus 5% (12).
Percentages can be swapped: 8% of 50 is the same as 50% of 8, which is 4. Use whichever order is easier to do in your head.
Percent versus percentage points
If an interest rate goes from 4% to 5%, it has risen by one percentage point but by 25 percent, because 1 is 25% of 4. Mixing the two up is one of the most common mistakes in news stories and reports.
Questions people ask
What is 20% of 150?
30. Multiply 150 by 0.20, or take 10% (15) and double it.
45 is what percent of 60?
75%. Divide 45 by 60 to get 0.75, then multiply by 100.
30 is 25% of what number?
120. Divide 30 by 0.25. A quick check: a quarter of 120 is 30.
How do I turn a percent into a decimal?
Divide by 100, which moves the decimal point two places left. 15% is 0.15 and 7.5% is 0.075.