This percentage calculator answers the everyday question “what is X% of Y?” Use it for discounts, taxes, tips, test scores, commissions, interest and statistics. Enter the percentage and the number, and the result appears instantly.
To find a percentage of a number, divide the percentage by 100 and multiply by the number. For example, 15% of 200 = (15 ÷ 100) × 200 = 30. The calculator does this for you automatically.
25% of 640 is 160. 8% of 150 is 12. Change either field and the answer recalculates in real time.
To find a percentage change, subtract the old value from the new, divide by the old value, and multiply by 100. A rise from 80 to 100 is a 25% increase, while a fall from 100 to 80 is a 20% decrease — the base is different, which is why the two figures do not match.
If 30 is 15% of a number, divide 30 by 0.15 to get 200. Reverse percentages help you find an original price before a discount or a total before tax.
The same operation — part = whole × percent ÷ 100 — covers tips, sales tax, VAT, interest, exam scores, nutrition labels and statistics. Learn it once and every percentage problem becomes the same.