Percentage Calculator
Three percentage calculators in one — find X% of Y, what % is X of Y, and percentage change.
How to calculate percentage
The core percentage formula is Percentage = (Part ÷ Whole) × 100. Whenever you need to figure out the percentage of a number, identify the part and the whole, divide, then multiply by 100. Here are four worked examples covering the most common situations.
Convert the percent to a decimal and multiply: (20 ÷ 100) × 500 = 0.2 × 500 = 100. So 20% of 500 is 100.
Divide the part by the whole, then multiply by 100: (45 ÷ 60) × 100 = 0.75 × 100 = 75%. So 45 is 75% of 60.
Find the difference, divide by the original, multiply by 100: ((100 − 80) ÷ 80) × 100 = (20 ÷ 80) × 100 = 25% increase.
Treat marks scored as the part and total marks as the whole: (425 ÷ 500) × 100 = 0.85 × 100 = 85%.
Common percentage conversions
A quick reference for converting everyday fractions to percentages, plus common percentages of 1000. Memorising these makes mental percentage calculation much faster.
| Fraction | Percentage | Decimal |
|---|---|---|
| 1/2 | 50% | 0.5 |
| 1/3 | 33.33% | 0.3333 |
| 2/3 | 66.67% | 0.6667 |
| 1/4 | 25% | 0.25 |
| 3/4 | 75% | 0.75 |
| 1/5 | 20% | 0.2 |
| 1/8 | 12.5% | 0.125 |
| 1/10 | 10% | 0.1 |
| Percentage | of 1000 |
|---|---|
| 5% | 50 |
| 10% | 100 |
| 15% | 150 |
| 20% | 200 |
| 25% | 250 |
How percentages work
A percentage is a fraction expressed out of 100. "Per cent" literally means "per hundred" in Latin. Percentages are used everywhere from exam marks to GST rates to sale discounts.
Common percentage calculations in India
GST rates in India are 0%, 5%, 12%, 18% or 28%. Use "X% of Y" to find how much GST to add to a base price.
If you scored 432 out of 600, use "X is what % of Y" to find your percentage: 432 ÷ 600 × 100 = 72%.
If your salary rose from ₹50,000 to ₹58,000, the hike percentage is (8000 ÷ 50000) × 100 = 16%.
Frequently asked questions
What is the difference between percentage and percentile?
A percentage is a fraction of a whole, expressed out of 100 (e.g., you scored 72%). A percentile is a ranking position — scoring in the 90th percentile means you scored higher than 90% of all test-takers, regardless of the actual score.
How do I calculate GST-inclusive price from GST-exclusive price?
If GST rate is 18%, the inclusive price = exclusive price × 1.18. To find the exclusive price from an inclusive price: exclusive = inclusive ÷ 1.18. This is sometimes called "reverse GST" calculation.
What does a negative percentage change mean?
A negative percentage change means the new value is lower than the old value — a decrease. For example, if a product's price drops from ₹1000 to ₹750, the change is −25%.
Can percentage change exceed 100%?
Yes. If something doubles in value, the percentage increase is 100%. If it triples, it is 200% increase. There is no upper limit. However, something can only decrease by a maximum of 100% (to zero).
How do I calculate a percentage of a percentage?
Multiply the two percentages and divide by 100. For example, 20% of 15% = (20 × 15) ÷ 100 = 3%. This is useful for compound discount calculations.
How do I calculate percentage of marks?
Divide the marks you scored by the total marks, then multiply by 100. For example, if you scored 425 out of 500, your percentage is (425 ÷ 500) × 100 = 85%. For multiple subjects, add up all marks scored and divide by the total maximum marks before multiplying by 100.
What is the percentage formula?
The basic percentage formula is Percentage = (Part ÷ Whole) × 100. To find X% of a number, use (X ÷ 100) × Number. To find what percent one number is of another, use (Part ÷ Whole) × 100.
How to calculate percentage increase?
Subtract the original value from the new value, divide the result by the original value, then multiply by 100. Formula: ((New − Old) ÷ Old) × 100. For example, an increase from 80 to 100 is ((100 − 80) ÷ 80) × 100 = 25%.