Discount Calculator
Find your sale price, savings, or discount percentage — instantly.
How to calculate a discount
Calculating a discount is straightforward once you know the formula. Subtract the discount percentage from 100%, then multiply that by the original price:
Sale Price = Original Price × (1 − Discount% ÷ 100)
For example, a 30% discount on a $120 item: $120 × (1 − 0.30) = $120 × 0.70 = $84.
You save $36.
Discount percentage formula
If you already know the original and sale prices and want to find the discount percentage, use:
Discount% = ((Original − Sale) ÷ Original) × 100
Example: original $80, sale $60. Discount% = ((80 − 60) ÷ 80) × 100 = 25%.
Find the original price from a sale price
If you see a sale price and know the percentage off, recover the original price with:
Original Price = Sale Price ÷ (1 − Discount% ÷ 100)
Example: $75 after 25% off → $75 ÷ 0.75 = $100 original.
Common discounts quick-reference
| Original | 10% off | 20% off | 25% off | 30% off | 50% off |
|---|---|---|---|---|---|
| $25 | $22.50 | $20.00 | $18.75 | $17.50 | $12.50 |
| $50 | $45.00 | $40.00 | $37.50 | $35.00 | $25.00 |
| $100 | $90.00 | $80.00 | $75.00 | $70.00 | $50.00 |
| $200 | $180.00 | $160.00 | $150.00 | $140.00 | $100.00 |
| $500 | $450.00 | $400.00 | $375.00 | $350.00 | $250.00 |
Frequently asked questions
What is 20% off $100?
20% off $100 is $80. You save $20. Calculation: $100 × 0.80 = $80.
How do I calculate 30% off?
Multiply the price by 0.70. For $60: $60 × 0.70 = $42. You save $18.
What does "double discount" mean?
A double discount applies two reductions sequentially, not additively. "20% off then an extra 10% off" means: price × 0.80 × 0.90 = price × 0.72 — effectively 28% off, not 30%.
How does this calculator work?
This calculator runs entirely in your browser — no data is sent anywhere. Results update on every keystroke. Use the Share button to copy a link with your inputs encoded so you can bookmark it or send it to someone.