Percentage Calculator
15% of 80
12
- 80 plus 15%
- 92
- 80 minus 15%
- 68
Show how it’s worked outHide working
80 × 15 ÷ 100 = 12.
About Percentage
"Percent" means "per hundred", so every percentage question is a ratio scaled to 100. The three questions people actually ask are covered here.
X% of Y: multiply and divide by 100 — 15% of 80 is 80 × 15 ÷ 100 = 12. Useful for discounts, tax and tips.
X is what % of Y: divide and multiply by 100 — 30 is 30 ÷ 120 × 100 = 25% of 120. Useful for scores and shares.
Percentage change: (new − old) ÷ old × 100 — going from 50 to 65 is a 30% increase. Note the asymmetry: a 50% drop needs a 100% rise to get back. Percent difference (shown as an extra) compares two values without treating either as the starting point, dividing by their average instead.
Common questions
- How do I find a percentage of a number?
- Multiply the number by the percentage and divide by 100. 15% of 80 is 80 x 15 / 100 = 12.
- How do I calculate percentage change?
- Subtract the old value from the new value, divide by the old value, and multiply by 100. Going from 50 to 65 is (65 - 50) / 50 x 100 = 30% increase.