Home Percentage calculator
Percentage calculator
Work out a percent of a number, what percent one number is of another, and the percent change. Results round to 8 decimal places. Numbers stay in this browser.
Why this exists
The discount calculator turns a list price and a percent off into a sale price. This page answers a ratio and a change.
From 100 to 80 is 20% down, and from 80 to 100 is 25% up. The two directions are not the same percent.
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01How to use it
Pick a tab and type the two numbers. 15 and 80 are the first example.
The large line states the question and the result. A change is marked increase, decrease, or no change.
Copy puts that line on the clipboard. Closing the tab clears the numbers.
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02What you get
15% of 80 is 12. 12 is 15% of 80.
80 to 100 is a 25% increase, and 100 to 80 is a 20% decrease. 200% of 40 is 80.
Entered15% of 80 = 12
15% of 80 12 12 is what percent of 80 15% 80 → 100 25% increase 100 → 80 20% decrease -
03Worth knowing
A negative percent is allowed. −10% of 80 is −8.
Trailing zeros are dropped, so 12.00000000 is shown as 12.
A ratio whose second number is 0, or a change whose starting number is 0, is refused.
This is not the discount calculator. 30% off a list price of 100 belongs on that page.
Questions
- QIs 15% of 80 equal to 12?
- AYes. 80 times 15, divided by 100, is 12.
- QIs 100 to 80 a change of 20%?
- AIt is a 20% decrease. The other way, 80 to 100, is a 25% increase.
- QCan the percent be over 100?
- AYes. 200% of 40 is 80.
- QAre the numbers saved?
- ANo. They stay in this browser and are not sent to a server.
How this page works it out
This page answers three questions: a percent of a number, what percent one number is of another, and the change from one number to the next. 15% of 80 multiplies 80 by 15 and divides by 100, which is 12. 12 is 15% of 80.
From 80 to 100 is a 25% increase, and from 100 to 80 is a 20% decrease. Reversing the direction does not keep the same percent. 200% of 40 is 80, and −10% of 80 is −8. The screen rounds to 8 decimal places, drops trailing zeros, and uses a dot as the decimal mark.
A ratio whose second number is 0, or a change whose starting number is 0, is refused. Taking a percent off a list price to reach a sale price belongs on the discount calculator. The numbers stay in this browser and are not sent to a server.