What Is X% of Y?

Calculate percentages instantly, with the working shown. Switch between the four calculators above the inputs.

X% of Y X is what % of Y % change % off

Percent Number

Percentage formulas

X% of Y = X ÷ 100 × Y. Example: 15% of 80 = 12
X is what % of Y = X ÷ Y × 100. Example: 12 is 15% of 80
% change = (new − old) ÷ old × 100. Example: 50 to 75 is +50%
Price after X% off = price × (100 − X) ÷ 100. Example: 20% off 50 = 40

"Percent" means "per hundred": 15% is 15/100, or 0.15. Percentage points measure the difference between two percentages: a rate going from 4% to 5% rises by 1 percentage point, which is a 25% increase.

Common percentages

	10%	15%	20%	25%	50%	75%
20	2	3	4	5	10	15
40	4	6	8	10	20	30
50	5	7.5	10	12.5	25	37.5
60	6	9	12	15	30	45
80	8	12	16	20	40	60
100	10	15	20	25	50	75
120	12	18	24	30	60	90
150	15	22.5	30	37.5	75	112.5
200	20	30	40	50	100	150
250	25	37.5	50	62.5	125	187.5
500	50	75	100	125	250	375
1,000	100	150	200	250	500	750

Popular discounts

Percent of a number · What percent · Percentage change · Discounts · Percent to fraction

Frequently asked questions

How do you calculate a percentage of a number?

Divide the percentage by 100 and multiply by the number: 15% of 80 = 0.15 × 80 = 12.

How do you find what percent one number is of another?

Divide the part by the whole and multiply by 100: 12 is 12 ÷ 80 × 100 = 15% of 80.

How do you calculate percentage change?

Subtract the old value from the new one, divide by the old value and multiply by 100: from 50 to 75 is (75 − 50) ÷ 50 × 100 = +50%.

How do you calculate a discount?

Multiply the price by the discount percentage to get the savings, then subtract: 20% off $50 saves $10, so you pay $40. Or multiply by (100 − discount)%: 50 × 0.8 = 40.

Is 10% of 50 the same as 50% of 10?

Yes. x% of y always equals y% of x, which is a handy trick: 8% of 25 is the same as 25% of 8, which is 2.