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Percentage calculator
Four everyday percentage sums. Type in any box and the answer updates straight away.
What is X% of Y?
Answer0
X is what % of Y?
Answer0%
Percentage change from A to B
Change0%
Difference0
Add or take off a percentage
Result0
Amount of change0
The formulas
X% of Y = Y × X ÷ 100 · X as % of Y = X ÷ Y × 100 · change = (B − A) ÷ A × 100Worked examples
A 15% tip on an $80 bill is $12. Scoring 30 out of 120 is 25%. Rent going from $80 to $100 a night is a 25% increase. A $250 jacket at 30% off costs $175.
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Common questions
How do I work out a percentage of a number?
Multiply the number by the percentage and divide by 100. For example, 15% of 80 is 80 × 15 ÷ 100 = 12.
How do I work out percentage change?
Take the new value minus the old value, divide by the old value, then multiply by 100. Going from 80 to 100 is (100 − 80) ÷ 80 × 100 = a 25% increase.
Why doesn't a 20% rise then a 20% drop get me back to the start?
Because the drop is 20% of a bigger number. $100 up 20% is $120, and $120 down 20% is $96.
How do I take a discount off a price?
Use 'Add or take off a percentage' and choose minus. $250 with 30% off is $175.