Mera Hisab
How to calculate a percentage
"Percent" means "out of 100". The calculator above handles the three most common questions.
Percentage of a number
Result = Number × Percentage ÷ 100
Example: 18% of 2,500 = 2,500 × 18 ÷ 100 = 450.
Percentage increase or decrease
Change % = (New value − Original value) ÷ Original value × 100
- Price goes from ₹80 to ₹100: (100 − 80) ÷ 80 × 100 = 25% increase.
- Price goes from ₹100 to ₹80: (80 − 100) ÷ 100 × 100 = 20% decrease.
The same ₹20 difference is 25% in one direction and 20% in the other, because the percentage is always worked out on the original value.
Marks percentage
Percentage = Marks obtained ÷ Total marks × 100
| Marks obtained | Total marks | Percentage |
|---|---|---|
| 425 | 500 | 85% |
| 512 | 600 | 85.33% |
| 380 | 650 | 58.46% |
Common mistakes
- Up and down are not equal. If a price rises 20% (₹100 → ₹120) and then falls 20%, it ends at ₹96, not ₹100.
- Percent vs percentage points. If an interest rate moves from 8% to 9%, it has risen by 1 percentage point, which is a 12.5% increase.
- Dividing by the wrong number. For percentage change, always divide by the original (old) value.
Quick mental tricks
- 10%: move the decimal point one place left (10% of 740 = 74).
- 5%: half of 10% (5% of 740 = 37).
- 25% and 50%: a quarter and a half.
- Swap trick: X% of Y equals Y% of X. So 8% of 50 = 50% of 8 = 4.
Frequently asked questions
How do I calculate my percentage of marks?
Divide the marks you obtained by the total marks and multiply by 100. For 425 out of 500: 425 ÷ 500 × 100 = 85%. Choose "Marks %" above to do it instantly.
How do I convert percentage to CGPA or CGPA to percentage?
It depends on your board or university, since each uses its own formula. Check the conversion rule printed on your marksheet or on your board's website.
How do I find the original value before a percentage increase?
Divide the new value by (1 + percentage ÷ 100). If a price is ₹600 after a 20% increase, the original price was 600 ÷ 1.2 = ₹500.
Can a percentage increase be more than 100%?
Yes. If a value goes from 50 to 150, it has increased by 200%. A decrease, however, can never be more than 100%.
Is the information I enter saved anywhere?
No. The calculation happens entirely in your browser. Nothing you enter is sent to our server or stored.