Percentage Calculator
Updated · Free · No sign-up · Runs in your browser
Four calculators in one: what is X% of Y, X is what percent of Y, percentage change (increase or decrease), and percent off for sale prices.
Results are rounded to two decimal places, and prices to the cent.
Percent off chart for a $100 item
| Discount | You pay | You save |
|---|---|---|
| 10% off | $90.00 | $10.00 |
| 15% off | $85.00 | $15.00 |
| 20% off | $80.00 | $20.00 |
| 25% off | $75.00 | $25.00 |
| 30% off | $70.00 | $30.00 |
| 40% off | $60.00 | $40.00 |
| 50% off | $50.00 | $50.00 |
| 60% off | $40.00 | $60.00 |
| 70% off | $30.00 | $70.00 |
Worked examples
What is 15% of 80?
- 80 × 15 ÷ 100
→ 12
20% off $59.99
- 59.99 × (1 − 0.20)
→ $47.99 (save $12.00)
50 → 65: percentage increase
- (65 − 50) ÷ 50 × 100
→ +30%
$80 item on sale for $60
- (80 − 60) ÷ 80 × 100
→ 25% off
Percentage formulas
- X% of Y = Y × X ÷ 100
- X is what percent of Y = X ÷ Y × 100
- Percentage change = (new − old) ÷ old × 100
- Sale price = original × (1 − discount ÷ 100); discount % = (original − sale) ÷ original × 100
Percent vs percentage points
When a rate rises from 3% to 5%, it went up by 2 percentage points, but by 66.67% in relative terms. Tick "both values are percentages" in the percentage change mode to see both.
Stacked discounts multiply rather than add: 30% off and then an extra 20% off is 0.7 × 0.8 = 0.56 of the price, a 44% discount — not 50%.
Frequently asked questions
How do I calculate a percentage of a number?
Multiply the number by the percentage and divide by 100. 25% of 200 = 200 × 25 ÷ 100 = 50.
How do I find what percent one number is of another?
Divide the part by the whole and multiply by 100. 30 is 25% of 120.
How do I calculate percentage increase?
Subtract the old value from the new value, divide by the old value and multiply by 100. From 40 to 50 is a 25% increase.
How do I calculate the price after a discount?
Multiply the price by (100 − discount) ÷ 100. 25% off $40 is $40 × 0.75 = $30.00.
Is 30% off plus 20% off the same as 50% off?
No. Discounts apply one after the other: 0.7 × 0.8 = 0.56, so you pay 56% — a total discount of 44%.
If a price rises 20% and then falls 20%, is it back to the original?
No. 100 → 120 → 96, so it ends 4% lower, because the 20% decrease is taken from the higher price.