TryutiloPercentage Calculator
Calculate percentage values, percentage rates and percentage changes: instantly, for free and without signup.
What is a percentage?
A percentage is a number expressed as a share of 100, written with the % sign. 30% means 30 out of every 100, or 0.30 as a decimal. This calculator performs three calculations: the percentage value of a number, the percentage rate that one number makes up of another, and the percentage change between an old and a new value. For example, 20% of 150 is 30, because 150 × 20 ÷ 100 = 30. In the other direction, 45 out of 150 is 30%, and a move from 80 to 100 is an increase of 25%. Choose the calculation type, enter two numbers and the result appears instantly. Everything runs in your browser, so the numbers you enter are not sent anywhere and nothing is stored. The same logic covers discounts and VAT, as the sections below show.
Percentage of a number
Multiply the number by the rate and divide by 100. 20% of 150 is 150 × 20 ÷ 100 = 30.
What percent one number is of another
Divide the part by the whole and multiply by 100. 45 out of 150 is 45 ÷ 150 × 100 = 30%.
Percentage change
Subtract the old value from the new one, divide by the old value and multiply by 100. Going from 80 to 100 is (100 − 80) ÷ 80 × 100 = an increase of 25%.
Discounts and VAT
A 30% discount on €80 leaves 70% to pay: 80 × 70 ÷ 100 = €56. VAT adds to the net price: 20% VAT on €250 is 250 × 20 ÷ 100 = €50, so the gross price is €300. To go back from gross to net, divide by 1.20: €300 ÷ 1.20 = €250.
How to use the percentage calculator
- Choose the type of calculation at the top: percentage of a number, percentage rate or change.
- Enter the two numbers you know. Decimals can be written with a dot or a comma.
- The result appears instantly. Use "Copy result" to put it on your clipboard.
The formulas of percentage calculation
Percentage calculation works with three quantities: the base value (the whole), the percentage rate (the share in %) and the percentage value (the share as a number).
Examples
| Task | Calculation | Result |
|---|---|---|
| 20% of 150 | 150 × 20 ÷ 100 | 30 |
| 45 out of 150 in percent | 45 ÷ 150 × 100 | 30% |
| From 80 to 100 | (100 − 80) ÷ 80 × 100 | +25% |
| 20% VAT on €250 | 250 × 20 ÷ 100 | €50 |
| 30% discount on €80 | 80 × 70 ÷ 100 | €56 |
| From 2% to 3% | 3 − 2 = 1 point; (3 − 2) ÷ 2 × 100 | +1 percentage point, +50% |
| From 100 to 80 | (80 − 100) ÷ 100 × 100 | −20% |
| Original price after a 30% discount (€56 paid) | 56 ÷ 0.70 | €80 |
Frequently asked questions
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. Example: 20% of 150 = 150 × 20 ÷ 100 = 30.
How do I work out a discount?
Subtract the discount from 100% and calculate with the remainder. A 30% discount on €80 gives 80 × 70 ÷ 100 = €56.
What is the difference between percent and percentage points?
If a value rises from 2% to 3%, that is an increase of 1 percentage point, but a rise of 50 percent.
How do I find the original price after a discount?
Divide the price you paid by the share that remained after the discount. If a 30% discount left you paying €56, you paid 70% of the original, so the original price is 56 ÷ 0.70 = €80. Adding 30% to €56 would give €72.80, which is wrong.
Why is a 20% decrease not undone by a 20% increase?
Because the second percentage is applied to a different base. 100 minus 20% is 80, and 80 plus 20% is 96, not 100. To get back to 100 you need an increase of 25%, since (100 − 80) ÷ 80 × 100 = 25%.
Are my inputs stored?
No. The calculation runs entirely in your browser. No inputs are sent to us.
Last updated: October 10, 2026
Maintained by the Tryutilo team. Calculations run in your browser, and nothing you enter is sent to a server.