Percentage Calculator
Three everyday percentage calculations in one place — pick a mode, enter two numbers, and see the answer with the formula used.
20% of 500
Formula used
The three percentage formulas
- X% of Y = (X ÷ 100) × Y. Example: 20% of ₹500 = (20 ÷ 100) × 500 = ₹100.
- X is what % of Y = (X ÷ Y) × 100. Example: 45 marks out of 60 = (45 ÷ 60) × 100 = 75%.
- % change from X to Y = ((Y − X) ÷ X) × 100. Example: a salary rises ₹40,000 → ₹46,000 = ((46,000 − 40,000) ÷ 40,000) × 100 = 15% increase.
Per cent literally means "per hundred". A percentage is just a fraction with 100 as the denominator — that's why dividing by 100 turns a percentage into the decimal you multiply with.
Percentages in everyday Indian life
Percentages run through daily life in India. Shopping discounts ("flat 30% off"), GST (5%, 12%, 18% or 28% on prices), salary appraisals ("a 12% hike"), board exam marks, FD and loan interest rates, and stock-market returns all speak percentages. Two traps catch people out. First, percentage points vs percent: a rate rising from 8% to 10% is a 2 percentage-point rise but a 25% relative increase. Second, compounding discounts: "20% off, then 10% off" is not 30% off — it's 28% off, because the second discount applies to the already-reduced price.
Worked examples
| Question | Calculation | Answer |
|---|---|---|
| 15% of ₹2,000 | (15 ÷ 100) × 2,000 | ₹300 |
| ₹850 is what % of ₹1,000? | (850 ÷ 1,000) × 100 | 85% |
| % change: ₹1,200 → ₹900 | ((900 − 1,200) ÷ 1,200) × 100 | 25% decrease |
| Original price after 20% discount to ₹800 | 800 ÷ (1 − 0.20) | ₹1,000 |
Frequently asked questions
How do I calculate X percent of Y?
Multiply X by Y and divide by 100. For example, 20% of 500 = (20 × 500) ÷ 100 = 100. Use the 'X% of Y' mode above.
How do I find what percentage one number is of another?
Divide the part by the whole and multiply by 100. For example, 45 marks out of 60 = (45 ÷ 60) × 100 = 75%. Use the 'X is what % of Y' mode above.
How do you calculate percentage increase or decrease?
Subtract the old value from the new value, divide by the old value and multiply by 100: ((New − Old) ÷ Old) × 100. A positive answer is an increase; a negative answer is a decrease. Use the '% change' mode above.
How do I reverse a percentage — find the original price after a discount?
Divide the discounted price by (1 − discount ÷ 100). If an item costs ₹800 after a 20% discount, the original price was 800 ÷ 0.8 = ₹1,000.
What is the difference between percentage points and percent?
A move from 10% to 15% is a 5 percentage-point rise but a 50% relative increase. Percentage points measure the absolute gap; percent measures the change relative to the starting value.