How to use the Discount Calculator
- ① Sale price: enter the original price and the discount rate to see what you actually pay and how much you save.
- ② Percent off: enter the original price and the sale price to see what percentage the discount is. This helps you check whether a store's sale is really a good deal.
- ③ Stacked discounts: enter the 1st and 2nd discounts (and a 3rd if you have one). The tool applies them in order and shows the final price and the real total discount.
Formulas for sale price and percent off
| What you want | Formula | Example |
|---|---|---|
| Amount saved | Original price × discount ÷ 100 | 30% of $59 = $17.70 |
| Sale price | Original price × (1 − discount ÷ 100) | $59 × 0.7 = $41.30 |
| Percent off | (Original price − sale price) ÷ original price × 100 | $89 → $62.30 = 30% |
For quick mental math, multiply by the share you still pay. For 30% off, multiply by 0.7. For 15% off, multiply by 0.85. That gives you the sale price right away.
Stacked discounts: 20% off plus an extra 10% off is not 30% off
"20% off, then an extra 10% off" does not take 30% off the original price. It takes 10% off the price that is already 20% lower.
- Original price $100 → 20% off → $80
- $80 → extra 10% off → $72
The final price is $72, so the real discount is 28%. As a formula: 1 − (1 − 0.2) × (1 − 0.1) = 1 − 0.72 = 0.28. Applying them in the other order (10% first, then 20%) gives the same result.
When a fixed-amount coupon such as "$5 off" is mixed in, though, the order matters. Calculate both ways, percentage discount first and then the $5 coupon, and the reverse, and compare the results.
Tips for comparing sale prices
- Check whether the "original" price is inflated. Comparing the final price with what other retailers charge is more reliable than looking at the percent off.
- Count shipping costs and rewards. A $6 shipping charge on a $40 item cuts the effective discount by 15 percentage points.
- Sales tax is often added at checkout in the US and Canada, so the price you pay can be higher than the sale price on the tag. In the UK and Australia, shelf prices usually already include VAT or GST.
- Buying from overseas? Account for exchange rates, import duties and taxes. Use the currency converter to turn foreign prices into your own currency before you compare.
- If you're not sure whether a price includes tax, the VAT calculator shows the price before and after tax.
Frequently asked questions
How much is 30% off?
Multiply the original price by 0.7. For example, 30% off $50 is $35. Enter the price and 30 in section ① to get the answer right away.
How do I find the discount percentage from the sale price?
Enter the original price and the sale price in section ②. The tool calculates the discount as (original price − sale price) ÷ original price × 100.
Is 50% off plus an extra 50% off free?
No. The second 50% comes off the price that is already halved, so you pay 25% of the original price. The total discount is 75%.
What does a discount percentage with decimals mean?
If an item that normally costs $39 is on sale for $29.90, the discount works out to about 23.33%. Stores usually round this down and advertise it as "23% off."
Can I find the original price from the sale price?
Yes. Divide the sale price by (1 − discount ÷ 100). For example, if something costs $35 after 30% off, the original price was $35 ÷ 0.7 = $50.
Does the order of stacked percentage discounts matter?
Not when every discount is a percentage. 20% then 10% gives the same final price as 10% then 20%. Order only matters when a fixed-amount coupon is involved.