Percentages run every business conversation — "sales are up 18%", "give me 12% off", "what's 5% of ₹2,34,000", "margin dropped from 32% to 27%, that's 5 points, not 5%". This calculator handles the six percentage questions that come up daily: X% of Y, what percent X is of Y, percentage change between two numbers, increase or decrease a number by a percentage, reverse a percentage (find the original), and percentage-point differences — with instant results and the formula shown so you can explain it to whoever asked.
The six calculations
| Question | Formula | Example |
|---|---|---|
| What is X% of Y? | Y × X ÷ 100 | 18% of ₹12,500 = ₹2,250 |
| X is what % of Y? | X ÷ Y × 100 | ₹3,400 of ₹20,000 = 17% |
| % change from A to B | (B − A) ÷ A × 100 | ₹80,000 → ₹94,000 = +17.5% |
| Increase/decrease Y by X% | Y × (1 ± X ÷ 100) | ₹1,499 less 30% = ₹1,049.30 |
| Original before a % change | B ÷ (1 ± X ÷ 100) | ₹1,180 after +18% → ₹1,000 |
| Percentage-point difference | B% − A% | 32% → 27% = −5 points (−15.6% relative) |
How to use it
- Pick the tab for the question you have.
- Type the numbers; results update as you type, with the formula shown beneath.
- Copy the result or the formula line into a message, a quote or a social post.
- Chain calculations — the result of one tab can be pushed into the next (for example, add 18% GST after a 30% discount).
Where each one shows up
- Discounts and GST: reverse-percentage is the one people get wrong. A price of ₹1,180 including 18% GST has a base of ₹1,000, not ₹967.60. The GST calculator and discount calculator apply this automatically.
- Growth reporting: month-on-month and year-on-year change; the revenue growth calculator annualises it and the CAGR calculator smooths multi-year growth.
- Margins: margin is profit ÷ price; markup is profit ÷ cost — the profit margin calculator shows both.
- Statutory rates: 12% PF on basic, 0.75% ESI, 8.33% bonus, 1% or 2% TDS — small percentages of large payrolls. The team payroll calculator applies them.
- Interest: 18% p.a. on late GST, 1% a month on advance-tax shortfalls, 3× bank rate under the MSMED Act — see late payment interest.
- Shares and splits: profit sharing between partners, commission splits, area-based charges in a society.
Percent vs percentage points
If your conversion rate moves from 4% to 5%, it rose by one percentage point and by 25% relative. Reports that mix the two mislead. The calculator shows both whenever you compare two percentages, which matters for margins, interest rates and tax rates alike.
Quick mental checks
- 10% = move the decimal one place; 5% = half of that; 1% = two places.
- 18% GST = 10% + 5% + 3% (₹1,000 → 100 + 50 + 30 = ₹180).
- A 20% discount followed by 20% markup does not return to the start: ₹100 → ₹80 → ₹96.
- To undo a p% increase you need a p ÷ (1 + p) decrease: undoing +25% needs −20%.
For the statutory percentages that changed recently, see GST 2.0 rate changes, TDS rates and thresholds for FY 2026-27 and Professional tax 2026: state-wise slabs.
Related tools
- Discount calculator — stacked offers and effective %.
- GST calculator — inclusive and exclusive tax.
- Revenue growth rate — period-over-period change.
- CAGR calculator — compound growth over years.
- Profit margin calculator — margin vs markup.