What is a Percentage Calculator?
A percentage calculator is a mathematical tool that helps you compute percentages quickly and accurately without doing manual arithmetic. Percentages are used constantly in everyday life — calculating discounts, tax amounts, tips, grade scores, interest rates, price changes, and much more. Our free percentage calculator offers five different calculation types all in one place, covering virtually every percentage problem you might encounter.
The 5 Calculation Types Explained
- What is X% of Y? — Find a percentage of a number. Example: What is 20% of 500? Answer: 100. Used for calculating discounts, commissions, and tips.
- X is what % of Y? — Find what percentage one number is of another. Example: 50 is what % of 200? Answer: 25%. Used for grades, market share, and ratios.
- Percentage Change from X to Y — Calculate how much a value increased or decreased in percentage terms. Example: From 100 to 150 = +50% increase. Used for comparing prices, sales figures, and growth rates.
- Increase/Decrease a number by % — Apply a percentage increase or decrease to a value. Example: 1000 increased by 15% = 1150. Used for salary hikes, price markup, and discounts.
- Find the whole from a part and percentage — If 50 is 25% of something, what is that something? Answer: 200. Useful for reverse engineering original prices after discount.
Real-World Examples
- Shopping Discount: A shirt costs ₹2,000 and has a 30% discount. What is the sale price? — 30% of 2000 = 600. Sale price = 2000 - 600 = ₹1,400
- Exam Score: You scored 72 out of 90 marks. What percentage did you get? — 72 is what % of 90? = 80%
- Salary Increase: Your salary is ₹50,000 and you got a 12% raise. New salary? — 50,000 increased by 12% = ₹56,000
- Tax Calculation: A product costs ₹800 before 18% GST. What is the final price? — 18% of 800 = 144. Final price = ₹944
- Profit Margin: You bought something for ₹1,200 and sold for ₹1,500. What is the profit %? — Percentage change from 1200 to 1500 = +25%
Frequently Asked Questions
How do I calculate percentage increase?+
Use the "Percentage Change from X to Y" calculator. Enter the original value as X and the new (higher) value as Y. The result will show the percentage increase. Formula: ((New - Old) / Old) × 100.
How do I find the original price after a discount?+
Use the "Find the whole" calculator (Type 5). If you paid ₹800 after a 20% discount, then ₹800 is 80% of the original price. Enter 800 as Y and 80 as X to find the original price of ₹1,000.
What is the difference between percentage and percentage points?+
A percentage point is an absolute difference between two percentages. If interest rates go from 5% to 7%, that is a 2 percentage point increase, but a 40% relative increase. These are very different — percentage points measure absolute change, percentages measure relative change.
How do I calculate percentage of marks?+
Use Type 2: "X is what % of Y?" Enter your marks obtained as X and total marks as Y. For example, if you scored 375 out of 500, enter X=375 and Y=500 to get 75%.
How accurate are the results?+
Results are calculated to 4 decimal places using standard JavaScript floating-point arithmetic. For all practical purposes (shopping, finance, school), the results are perfectly accurate. Trailing zeros are automatically removed for cleaner display.