Percentage Calculator
Percentage of a number, what percent one number is of another, or percentage change. A free online percentage calculator that works instantly in your browser, with no sign-up.
Covers the three percentage calculations people actually need — finding a percentage of a number, working out what percent one number is of another, and calculating percentage increase or decrease between two values. Results appear as you type, and every calculation has its own link you can bookmark or send to someone.
How to calculate a percentage
- Pick the calculation. Choose "X% of Y" to find a percentage of a number, "X is what % of Y" to turn a score into a percentage, or "% change" to compare two values.
- Enter your two numbers. Type the values into the two fields. The result updates as you type — there is no calculate button to press.
- Read or share the result. The answer appears immediately, along with the difference. Use Copy link to share the exact calculation with someone else.
The three percentage formulas
Percentage of a number. Divide the percentage by 100 and multiply by the value: 15% of 200 is (15 ÷ 100) × 200 = 30. This is the one behind discounts, tips, and commission.
What percent one number is of another. Divide the part by the whole and multiply by 100: 45 out of 60 is (45 ÷ 60) × 100 = 75%. This is how test scores, completion rates, and shares of a total are worked out.
Percentage change. Subtract the old value from the new one, divide by the old value, and multiply by 100: from 80 to 100 is (100 − 80) ÷ 80 × 100 = a 25% increase. A negative result is a decrease. Note that the old value is always the denominator, which is why a rise and the fall that undoes it are different percentages.
Frequently asked questions
How do I find what percentage one number is of another?
Use the "X is what percent of Y" mode — enter both numbers and the calculator returns the percentage directly. For example, 45 out of 60 is 75%.
How is percentage change calculated?
Percentage change is (new value − old value) ÷ old value × 100, and the calculator handles both increases and decreases. Going from 80 to 100 is a 25% increase; going from 100 to 80 is a 20% decrease.
Can I calculate a percentage of a number, like 15% of 200?
Yes — that's the calculator's default mode: enter the percentage and the number to get the result instantly. 15% of 200 is 30.
How do I work out a percentage discount?
Use "X% of Y" with the discount rate and the original price to get the amount off — 20% of ₹2,500 is ₹500, so the sale price is ₹2,000. The Remaining row shows that final figure directly.
Why is a percentage increase and decrease of the same size not symmetrical?
Because each is measured against a different starting value. A 50% rise from 100 gives 150, but returning from 150 to 100 is a 33.3% fall — the second calculation divides by 150, not 100.
Can I share a calculation with someone?
Yes. The inputs are stored in the page's web address, so the Copy link button gives you a URL that reopens the calculator with the same numbers already filled in.