How do I find a percentage of a number?
Divide the percentage by 100 and multiply by the number. 15% of 200 is (15 / 100) × 200 = 30.
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Percentage calculator
Find a percentage of a number, what percent one number is of another, and percentage change.
part = (p/100)·whole ; p = (part/whole)·100
Frequently asked questions
How do I work out what percentage one number is of another?
Divide the part by the whole and multiply by 100. 30 out of 200 is (30 / 200) × 100 = 15%.
What is percentage change?
It measures how much a value grew or shrank, as a percentage of the original: (new − old) / old × 100. From 120 to 150 is a 25% increase.
Where is this used in real life?
Shopping discounts — a 30% off $80 jacket saves 0.30 × 80 = $24. Exam scores — 45 out of 60 is (45/60) × 100 = 75%. Tax and tips — a 10% GST on a $50 bill adds $5. Percentages turn up anywhere two amounts are compared as 'out of a hundred'.
Why is the pie chart useful here?
The shaded slice is the part you calculated and the rest is what remains, so you can see at a glance how big the percentage is relative to the whole.