Percentage Calculator
Five calculators in one — percentage of a number, percentage change, adding or removing a percentage, and reverse percentage.
- Free — no sign-up
- Instant, on-screen results
- Built by our CA · CS team
- Rules cited on the page
Enter your figures — the result on the right updates as you type.
Working out GST, TDS or a salary hike?
Get the actual tax number checked by a CA — not just the percentage.
Disclaimer: This is a general arithmetic tool. For tax percentages such as GST, TDS or interest under Sections 234A/B/C, use the dedicated TaxClue calculator — those involve thresholds, rounding and cess rules that a plain percentage does not capture.
The five percentage questions
Almost every percentage problem is one of five shapes. Once you can spot which one you are looking at, the formula follows automatically — and the mistake people make is nearly always picking the wrong base (the number the percentage is “of”).
| Question | Formula |
|---|---|
| What is X% of Y? | Y × X ÷ 100 |
| X is what percent of Y? | X ÷ Y × 100 |
| Percentage change (old → new) | (New − Old) ÷ Old × 100 |
| Add X% to Y | Y × (1 + X ÷ 100) |
| Remove X% from a total | Total ÷ (1 + X ÷ 100) |
Worked example
A salary rises from ₹50,000 to ₹57,500 a month. Three different percentage questions come out of the same two numbers.
Key terms explained
Base value
The number the percentage is measured against. In “X% of Y”, Y is the base. Almost every percentage error is a wrong base — comparing against the new value instead of the old, for instance.
Percentage vs percentage point
If a rate moves from 10% to 12%, that is a rise of 2 percentage points but 20 percent. News reports and loan documents mix these up constantly.
Reverse percentage
Recovering the original from an inflated total — dividing by (1 + rate), not subtracting. Used for removing GST from an inclusive price or grossing up a net-of-TDS payment.
Compounding percentages
Two successive 10% rises are not 20% — they are 21% (1.1 × 1.1). Stacked discounts, annual hikes and interest all compound this way.
How the Percentage Calculator works
4 steps, start to finish — the same order the tool follows.
- 01Pick the mode that matches your question.
- 02Enter the two numbers the mode asks for.
- 03Read the answer and the formula used, worked out in full.
- 04Switch modes to check the same figures a different way.
Questions people ask
Short answers on Percentage Calculator. Tap a question to open it.
01How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. 18% of ₹25,000 is 25,000 × 18 ÷ 100 = ₹4,500. This is the same arithmetic as computing GST at 18% or a TDS rate on a payment.
02How do I work out percentage increase or decrease?
Percentage change = (new value − old value) ÷ old value × 100. A salary moving from ₹50,000 to ₹57,500 is a 15% increase; from ₹57,500 back to ₹50,000 is a 13.04% decrease — the two are not the same number because the base changes.
03How do I find the original amount before a percentage was added?
Divide by (1 + rate ÷ 100). An invoice of ₹11,800 including 18% GST has a base of 11,800 ÷ 1.18 = ₹10,000, and the GST is ₹1,800. Subtracting 18% of ₹11,800 gives the wrong answer.
04What is the difference between percentage and percentage points?
If a rate moves from 10% to 12%, that is a rise of 2 percentage points but a 20% increase in the rate itself. Interest rates, tax rates and margins are usually quoted in percentage points to avoid the ambiguity.
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Disclaimer: This tool gives indicative results for general guidance only and is not professional advice. Please verify with a qualified CA before acting on the numbers.