The Percentage Calculator handles the three most common percentage questions in one place: what is X% of a number, what percent one number is of another, and the percentage increase or decrease between two numbers. Type your values and each answer appears instantly.
Percentages come up everywhere — discounts and sales, tax and GST, tips, exam marks, interest, and statistics. This tool saves you the mental arithmetic and shows the full sentence so the result is easy to read and copy. Everything runs in your browser.
How to use the percentage calculator
- For “X% of a number”, enter the percentage and the number to get the amount.
- For “X is what percent of Y”, enter the part and the whole to get the percentage.
- For percentage change, enter the original value and the new value to see the increase or decrease.
- All three calculators update live as you type — no button to press.
How to calculate percentages
- X% of Y = (X ÷ 100) × Y. Example: 15% of 200 = (15 ÷ 100) × 200 = 30.
- X is what % of Y = (X ÷ Y) × 100. Example: 30 is (30 ÷ 150) × 100 = 20% of 150.
- Percentage change = ((new − old) ÷ old) × 100. Example: from 80 to 100 = ((100 − 80) ÷ 80) × 100 = +25%.
Everyday examples
- Discount: a 20% discount on ₹1,500 saves ₹300 (20% of 1500).
- Exam score: 45 out of 60 marks is 75% (45 ÷ 60 × 100).
- Price rise: a product going from ₹200 to ₹250 is a 25% increase.
- Tip: a 10% tip on a ₹800 bill is ₹80.
Frequently Asked Questions
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. For example, 15% of 200 is (15 × 200) ÷ 100 = 30. The first calculator on this page does it for you.
How do I find what percentage one number is of another?
Divide the first number by the second and multiply by 100. For example, 30 out of 150 is (30 ÷ 150) × 100 = 20%.
How do I calculate percentage increase or decrease?
Subtract the original value from the new value, divide by the original value, then multiply by 100. A positive result is an increase and a negative result is a decrease.
How do I calculate a discount?
Use “what is X% of a number”: enter the discount percentage and the original price to see how much you save, then subtract that from the price for the final amount.
Is the calculator free and private?
Yes. It is completely free and all calculations happen in your browser — nothing you type is sent to a server or stored.