Percentage Calculator
Calculate any percentage instantly — find what % of a number is, calculate % change, reverse percentage, and more. 6 calculators in one tool.
How to calculate percentages
What is X% of Y? Divide X by 100, then multiply by Y. Example: 15% of 200 = (15÷100) × 200 = 30.
Percentage change: Subtract the old value from the new value, divide by the old value, multiply by 100. A positive result is an increase; negative is a decrease.
Common uses in India: GST calculation (add 5%, 18%, or 40%), discount calculation during sales, exam score percentages, EMI interest rates, salary hike percentages, and tipping at restaurants.
Tip: To quickly find 10% of any number, just move the decimal point one place to the left. 10% of 450 = 45. Then multiply for other percentages — 20% = double of 10%, 5% = half of 10%.
Percentages made simple — with real Indian examples
Almost every percentage question is one of four types. Once you can spot which one you're facing, the arithmetic is easy — and this calculator handles all four, but knowing the method means you'll never be fooled by a misleading "sale" sign or a confusing pay-slip again.
1. Finding a percentage of a number
The everyday case — a discount, a GST amount, a tip. Divide the percentage by 100 and multiply. 18% of ₹2,000 = (18 ÷ 100) × 2,000 = ₹360. A quick mental shortcut: 10% is just the number with the decimal moved one place left, so 10% of ₹450 is ₹45 — then scale from there (5% is half of that, 20% is double).
2. What percentage is one number of another?
This is how marks and scores work. Divide the part by the whole and multiply by 100. 45 out of 180 = (45 ÷ 180) × 100 = 25%. Students use this constantly for aggregate marks across subjects — add all marks obtained, divide by total maximum marks, times 100.
3. Percentage increase and decrease
For a salary hike or a price change: subtract old from new, divide by the old value, multiply by 100. A jump from ₹50,000 to ₹55,000 is (5,000 ÷ 50,000) × 100 = 10%. Always divide by the starting value, not the ending one — dividing by the wrong base is the most common slip here.
4. Reverse percentage — the one most people get wrong
If you know the final amount and want the original, you cannot just subtract the percentage.
Percentage points vs percent — a costly confusion
Where you'll use this in daily life
- Students: aggregate marks, converting CGPA to percentage, exam cut-offs.
- Shoppers: real savings on a discount, and spotting when a "50% + 10%" offer isn't actually 60% off (it's 55%).
- Salaried professionals: hike percentages, tax proportions, take-home ratios.
- Business: GST, profit margins, and markups — for GST specifically, our GST calculator handles the add/remove split directly.
Frequently asked questions
How do I calculate percentage of marks?
Add up all the marks you obtained, divide by the total maximum marks, and multiply by 100. For 380 out of 500, that's (380 ÷ 500) × 100 = 76%.
How do I remove GST or a tax from a total?
Divide the inclusive total by 1 plus the rate as a decimal. For 18%, divide by 1.18. Subtracting 18% directly gives the wrong answer because the tax was calculated on the smaller base price.
Is a "50% + 10%" discount the same as 60% off?
No. The second discount applies to the already-reduced price. On ₹1,000, fifty percent off is ₹500, then ten percent off that is ₹450 — an effective 55% discount, not 60%.
What's the difference between percent and percentage points?
A move from 5% to 7% is two percentage points, but a 40% increase relative to the original 5%. Percentage points measure the absolute gap; percent measures the change relative to the starting value.
How do I calculate a percentage increase?
Subtract the original from the new value, divide by the original, and multiply by 100. Always divide by the starting number, not the final one.