Percentage Calculator
Percent of a number, percent share and percent change.
- Working
- 15 ÷ 100 × 80
How this calculator works
Pick the question you want answered and enter two numbers. The result updates as you type.
Formula
X% of Y = X ÷ 100 × Y; share = X ÷ Y × 100; change = (Y − X) ÷ |X| × 100
Example
15% of 80 is 12. A price that rises from 80 to 92 has increased by 15%.
When to use it
- Discounts and sales tax
- Grade and score percentages
- Price and salary changes
Frequently asked questions
How do I calculate a discount?
Multiply the price by the discount percentage and subtract the result. A 20% discount on $50 is $50 − $10 = $40.
Why doesn't a 50% rise and a 50% fall cancel out?
Each percentage applies to a different base. 100 rises to 150, then falling 50% of 150 leaves 75.
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