Toolstia / Percentage calculator
Percentage calculator
Five common percentage questions on one page: what is X% of Y, what percent is X of Y, the percent change between two numbers, and adding or subtracting a percent. Results update as you type.
What is X% of Y?
X is what percent of Y?
Percent change from X to Y
Add a percent (tax, markup)
Subtract a percent (discount)
How it works
- Find the box that matches your question.
- Fill in both numbers.
- Read the answer under the boxes.
Percent of a number
For 15% of 200, enter 15 and 200 in the first box. The answer is 30.
What percent is one number of another
If you scored 45 out of 60, enter 45 and 60 in the second box. The answer is 75%.
Percent change
From 80 to 100 is a 25% increase, found by dividing the change (20) by the starting value (80). From 100 to 80 is a 20% decrease. The two are not equal because the starting value differs.
Discounts, tax and markup
Use "Add a percent" for tax or markup and "Subtract a percent" for a discount. A 20% discount on 150 gives 120.
Questions
Why is a 20% decrease not undone by a 20% increase?
Because each percentage applies to a different starting number. A 20% cut from 100 gives 80, and a 20% rise from 80 gives 96.
Can I use decimals?
Yes. Use a dot, for example 7.5.
What does "Check the numbers" mean?
One of the entries is not a number, or the calculation would divide by zero.