How to use Percentage Calculator
- Choose what you want to calculate.
- Type the two values; the result appears as you type.
- Read the explanation under the result to understand the operation.
Tips and limits
- You can use a comma or a period for decimals.
- In “% change”, a negative result means the value went down.
- To add tax to a price, use “Increase or decrease”.
What it is for and how it works
A percentage is a fraction of one hundred. Saying “25%” is the same as saying “25 out of every 100” or multiplying by 0.25. Almost every everyday calculation — discounts, tips, interest, price changes — is a variation of that idea.
This calculator covers five cases: percentage of an amount, what percentage a number represents, change between two values, increase or decrease, and finding the total when you know a part.
Frequently asked questions about Percentage Calculator
How do you calculate X% of an amount?
Multiply the amount by X and divide by 100. For example, 15% of 200 is 200 × 15 ÷ 100 = 30.
How do you calculate a percentage change?
Subtract the starting value from the final one, divide by the starting value and multiply by 100.
Why does going up 20% and down 20% not return to the start?
Because the second percentage is calculated on a different value. 100 rises to 120 and, after falling 20%, ends at 96.