What is a Percentage Calculator?
The two percentage questions everyone needs: what a percentage of a number is (discounts, tips, marks), and what percentage one number is of another (scores, shares, growth).
Both forms sit side by side and compute live — no button, no rounding surprises.
The three real-world shapes: discounts (20% off Rs 1,499 leaves Rs 1,199.20), score conversion (438 out of 500 is 87.6%), and share-of-total (your team closed 34 of 120 tickets — 28.3%). All are the same two formulas this page computes live; the skill is recognizing which question you are actually asking.
How to use the Percentage Calculator
- Fill either row’s two numbers.
- Read the live result beside it.
- Adjust values to explore.
Frequently asked questions
How do successive discounts combine?
Multiplicatively, not additively: 20% off then 10% off leaves 0.8 x 0.9 = 72% of the original — a 28% total discount, not 30%. Retailers count on the confusion.
How do I add a percentage to a number?
Multiply by (1 + rate): adding 18% to 1,000 is 1,000 x 1.18 = 1,180. The same logic in reverse is why removing GST divides rather than subtracts.
How do I calculate X% of Y by hand?
Multiply: Y × X ÷ 100. 15% of 200 = 200 × 15 ÷ 100 = 30.
How do I find what percent X is of Y?
Divide and scale: X ÷ Y × 100. 30 of 200 → 15%.
Can results exceed 100%?
Yes — 250 is 125% of 200. Percentages above 100 just mean “more than the whole”.
For percentage increase or decrease?
That is its own formula — use the Percentage Change Calculator.