Calculate percentages instantly with step-by-step breakdowns. Supports percentage of a number, percentage change, difference, and add/subtract operations.
Formula: Result = (Percentage / 100) × Number
| % | of 100 | of 500 | of 1,000 | of 5,000 | of 10,000 |
|---|---|---|---|---|---|
| 10% | 10 | 50 | 100 | 500 | 1,000 |
| 15% | 15 | 75 | 150 | 750 | 1,500 |
| 20% | 20 | 100 | 200 | 1,000 | 2,000 |
| 25% | 25 | 125 | 250 | 1,250 | 2,500 |
| 33% | 33 | 165 | 330 | 1,650 | 3,300 |
| 50% | 50 | 250 | 500 | 2,500 | 5,000 |
| 75% | 75 | 375 | 750 | 3,750 | 7,500 |
The Percentage Calculator is a free browser-based tool that handles the four percentage operations people run into most often: finding what X% of Y is, working out what one number is as a percentage of another, calculating percentage increase or decrease between two values, and adding or subtracting a percentage from an amount. You type numbers into plain fields and the result updates instantly, with no sign-up and nothing sent to a server.
It is used by students checking homework, shoppers figuring out discounts and price hikes, finance and accounting staff computing margins or tax portions, and developers who just need a quick sanity check without opening a spreadsheet. Because every mode uses the same standard formulas, the answers match what you would get by hand or in Excel.
A percentage is simply a fraction expressed out of 100, so 25% means 25/100 or 0.25. To find X% of Y, the tool multiplies Y by X/100. For example, 20% of 150 is 150 x 0.20 = 30. To express one number as a percentage of another, it divides and multiplies by 100: 30 out of 150 is (30 / 150) x 100 = 20%.
Percentage change uses the formula ((new - old) / old) x 100. Going from 200 to 250 is ((250 - 200) / 200) x 100 = 25% increase; going from 250 to 200 is -20%. Note that a rise and the matching fall are not symmetric, because the base value differs each time.
Adding a percentage multiplies the base by (1 + X/100) and subtracting multiplies by (1 - X/100). So 200 plus 10% is 200 x 1.10 = 220, and 200 minus 10% is 200 x 0.90 = 180. All results are rounded for display but computed at full floating-point precision.
Use the 'X is what percent of Y' mode, entering the part first and the whole second. The tool computes (part / whole) x 100. For example, 45 out of 60 is 75%.
Because each percentage is applied to a different base. A 20% increase on 100 gives 120, but a 20% decrease on 120 gives 96, not 100. The decrease is taken from the larger number, so the two do not cancel.
Yes. You can enter decimal values like 12.5 or 3.75, and negative numbers are accepted for percentage change calculations where a value drops below zero.
'Percentage of' returns just the portion (10% of 200 is 20), while 'add a percentage' returns the total after the change (200 plus 10% is 220). Use the latter for markups, tips, or tax-inclusive prices.
Yes, it is completely free with no account required. All calculations run locally in your browser, so the numbers you enter are never uploaded or stored on any server.
Results are displayed rounded to a readable number of decimal places, but the underlying calculation uses full floating-point precision, so chained or exact math stays accurate.
Yes. Use the subtract mode: enter the original price and the discount percent to get the sale price. For example, 80 minus 25% gives a final price of 60.