Discount Calculator
Enter a price and a discount to see the sale price and how much you save. Stack extra discounts, add sales tax, or reverse the math to find the original price or the percent off.
How to use the Discount Calculator
- Enter the original price and the discount, either as a percentage or as an amount off.
- Stack extra discounts with "Add extra discount" if a coupon applies on top of a sale.
- Add sales tax (optional) to see the final price you'll pay at the till.
- Read the result: sale price, how much you save and the total discount, with the working shown step by step.
- Work backwards with the Original price tab (sale price + % off) or the % off tab (original + sale price).
Discount formulas
| To find | Formula | Example |
|---|---|---|
| Sale price | Price × (1 − % off ÷ 100) | $80 × 0.75 = $60 |
| Amount saved | Price × % off ÷ 100 | $80 × 0.25 = $20 |
| Original price | Sale price ÷ (1 − % off ÷ 100) | $60 ÷ 0.75 = $80 |
| Percent off | (Original − sale) ÷ original × 100 | ($120 − $84) ÷ $120 = 30% |
| Stacked discounts | Price × (1 − a) × (1 − b) | $100 × 0.7 × 0.8 = $56 (44% off) |
| Price with tax | Sale price × (1 + tax ÷ 100) | $60 × 1.08 = $64.80 |
Percent off chart
| Price | 10% off | 20% off | 25% off | 30% off | 40% off | 50% off |
|---|---|---|---|---|---|---|
| $20 | $18.00 | $16.00 | $15.00 | $14.00 | $12.00 | $10.00 |
| $50 | $45.00 | $40.00 | $37.50 | $35.00 | $30.00 | $25.00 |
| $75 | $67.50 | $60.00 | $56.25 | $52.50 | $45.00 | $37.50 |
| $100 | $90.00 | $80.00 | $75.00 | $70.00 | $60.00 | $50.00 |
| $150 | $135.00 | $120.00 | $112.50 | $105.00 | $90.00 | $75.00 |
| $200 | $180.00 | $160.00 | $150.00 | $140.00 | $120.00 | $100.00 |
Quick mental math: for 10% off, move the decimal point one place left and subtract. For 20% off, double that amount. For 25% off, divide by 4.
Frequently asked questions
How do I calculate a discount?
Multiply the price by the discount percentage and divide by 100 to get the amount saved, then subtract it from the price. For 25% off $80: 80 × 25 ÷ 100 = $20 saved, so the sale price is $60. A shortcut is price × (1 − discount ÷ 100), here 80 × 0.75 = $60.
How much is 20% off?
Multiply the price by 0.8. For example, 20% off $50 is $40, and 20% off $129.99 is $103.99.
How do stacked discounts work?
Each extra discount is applied to the already-reduced price, not the original. So 30% off plus an extra 20% off is 0.7 × 0.8 = 0.56 of the price, a total of 44% off rather than 50%.
Is sales tax added before or after the discount?
In most places sales tax is charged on the discounted price, so the calculator applies discounts first and then adds tax. Manufacturer coupons can be treated differently in some US states.
How do I find the original price from a sale price?
Divide the sale price by (1 − discount ÷ 100). If you paid $60 after 25% off, the original price was 60 ÷ 0.75 = $80. Use the Original price tab to do this automatically, even when tax is included.
How do I work out the percent off?
Subtract the sale price from the original, divide by the original and multiply by 100. From $120 down to $84: (120 − 84) ÷ 120 × 100 = 30% off.