Percentage Calculator
Percentages, shares, increases and decreases in one place.
A percentage calculator converts between a part and a whole expressed out of 100. This one covers the four questions that come up daily: what is X% of Y, X is what percent of Y, the percentage change from one value to another, and a value after adding a percentage. Pick a mode above and drag the two sliders.
Percentages are the language of marks and cut-offs, GST and discounts, salary hikes, interest rates and portfolio returns. Getting them right matters most when they compound or stack — a 20% rise followed by a 20% fall does not bring you back to where you started, and this calculator makes that easy to check.
The four percentage formulas
Percent of a value: value × percent ÷ 100. For 15% of 2,000 → 2,000 × 15 ÷ 100 = 300. What percent one number is of another: part ÷ whole × 100. For 45 out of 60 → 45 ÷ 60 × 100 = 75%, the mark you would report on a 60-mark paper.
Percentage change: (new − old) ÷ old × 100, where a negative answer is a fall. From 200 to 250 → (250 − 200) ÷ 200 × 100 = +25%, while from 250 back to 200 → (200 − 250) ÷ 250 × 100 = −20%. The two are not mirror images because the base changes — the classic reason a 25% hike followed by a 20% cut leaves you exactly where you began. Adding a percentage: value × (1 + percent ÷ 100), so ₹1,000 plus 18% GST is 1,000 × 1.18 = ₹1,180.
How to use this calculator
- Choose the mode that matches your question — the slider labels change with it.
- Drag either slider, or click the value pill and type an exact number.
- 'X% of Y' gives discounts, tips, commissions and shares of a total.
- 'X is what % of Y' converts marks, expenses or a category's spend into a percentage.
- '% change' compares before and after — a salary hike, a price rise or a portfolio move.
- 'Add %' applies GST, a service charge or an increment on top of a base value.
Percentages in Indian everyday money
GST rates of 5%, 12%, 18% and 28% are added on the taxable value, so a ₹1,000 invoice at 18% bills ₹1,180 — but MRP on a retail pack is already tax-inclusive, so the tax sits inside the price rather than on top of it. Salary hikes are quoted as a percentage of CTC, and a 30% hike on ₹12 lakh is ₹15.6 lakh CTC, not ₹15.6 lakh in hand. Bank interest, credit-card charges of 3–3.5% a month and lender processing fees of 0.5–2% are all percentage figures you can check here in a second.
Watch the base whenever percentages stack. A share that falls 50% needs a 100% gain to recover, so mutual fund fact sheets report absolute returns for periods under a year and CAGR beyond that. Marks work the same way: a 90% aggregate across five 100-mark papers is the total scored divided by 500, never the average of the five percentages when the papers carry different weights.
Frequently asked questions
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. For 15% of 2,000 that is 2,000 × 15 ÷ 100 = 300. Use the 'X% of Y' mode above and the answer updates as you drag the sliders.
How do I work out a percentage increase or decrease?
Subtract the old value from the new one, divide by the old value and multiply by 100. Going from 200 to 250 is a 25% increase; going from 250 back to 200 is a 20% decrease, because the starting point — the base — is different in each case.
Why isn't a 20% rise cancelled by a 20% fall?
The fall is applied to the larger number. ₹100 rising 20% becomes ₹120, and 20% off ₹120 is ₹96, not ₹100. To reverse a 20% rise you need a fall of 16.67%, which you can confirm in the '% change' mode.
How do I calculate my percentage of marks?
Divide the total marks you scored by the total maximum marks and multiply by 100 — use the 'X is what % of Y' mode. Never average individual subject percentages unless every paper carries the same maximum, as that gives a different and incorrect figure.
How do I add GST to a price?
Use 'Add %' with the GST rate: ₹1,000 plus 18% is ₹1,180. To pull GST out of a tax-inclusive price instead, divide by 1.18 rather than subtracting 18%, or use our dedicated GST calculator.
What is the difference between percent and percentage points?
A move from 6% to 8% is a rise of 2 percentage points but a 33.3% increase in the rate itself. News reports on repo rates and inflation use percentage points, so read the wording carefully before comparing figures.
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Disclaimer: results are estimates based on the inputs and published rules/rates, for information only — not investment, tax or legal advice. Verify important decisions with a qualified professional. See our full disclaimer.