Discount Calculator
Free discount calculator. Enter the original price and discount percentage to see the final sale price and exactly how much you save.
You pay
$60.00
You save $20.00 (25%)
Original
$80.00
Total saved
$20.00
Retail pricing is designed to make arithmetic hard at the moment of decision. "30% off, extra 20% at checkout" is not 50% off, and a "buy two get one free" offer is not a third off each item. This calculator gives you the real final price and the real amount saved.
Enter the original price and the discount, and see the sale price, the money saved, and the effective percentage — including for stacked discounts.
How to use the Discount Calculator
Enter the original price
The pre-discount list price, before tax.
Enter the discount percentage
Or enter the sale price instead to find out what percentage the discount actually represents.
Read the final price and saving
You get the amount you pay and the amount you keep.
Add a second discount if the offer stacks
Two sequential discounts apply one after the other, not added together — the calculator shows the true combined rate.
The formulas
| To find | Formula | Example |
|---|---|---|
| Sale price | price × (1 − rate) | $80 at 25% off = $60 |
| Amount saved | price × rate | $80 × 0.25 = $20 |
| Discount rate | (saving ÷ original) × 100 | $20 off $80 = 25% |
| Original price | sale ÷ (1 − rate) | $60 after 25% off = $80 |
Stacked discounts are smaller than they look
When two discounts apply in sequence, the second is taken from the already-reduced price. "30% off plus an extra 20%" gives a total of 44%, not 50%.
On a $100 item: 30% off gives $70, then 20% off $70 gives $56. The general formula is 1 − (1 − d1) × (1 − d2).
| Advertised | Actual combined discount |
|---|---|
| 20% + 10% | 28% |
| 30% + 20% | 44% |
| 50% + 20% | 60% |
| 50% + 30% | 65% |
| 70% + 20% | 76% |
What multi-buy offers really discount
| Offer | Effective discount | Per-item price on a $30 item |
|---|---|---|
| Buy one get one free | 50% | $15 |
| Buy two get one free | 33.3% | $20 |
| Buy three get one free | 25% | $22.50 |
| Buy one get one half price | 25% | $22.50 |
| Second item 30% off | 15% | $25.50 |
These are only savings if you would have bought the extra items anyway. Buying two of something you needed one of at "50% off" means spending 100% more than you intended.
Recognising a fake discount
- Inflated reference prices. Some retailers raise the "was" price shortly before a sale. Price-history extensions and archived listings reveal this quickly.
- Permanent sales. If an item has been 40% off for six months, that is the actual price, not a discount.
- Order thresholds. "$20 off orders over $150" is 13% only if you genuinely wanted $150 of goods.
- Free shipping minimums that push you to add an unwanted item cost more than the shipping would have.
- Countdown timers that reset on reload are manufactured urgency, not a real deadline.
Discount then tax, or tax then discount?
The order does not change the final total, because multiplication is commutative — a $100 item with 20% off and 8% tax comes to $86.40 either way.
What does matter is that in the United States, sales tax is charged on the discounted price. If a receipt shows tax computed on the pre-discount amount, you have been overcharged.
Frequently asked questions
How do I calculate a discount?
Multiply the original price by the discount as a decimal to get the saving, then subtract it. 25% off $80 is $80 × 0.25 = $20 saved, leaving $60.
What do two stacked discounts add up to?
Less than their sum, because the second applies to the already-reduced price. 30% plus 20% equals 44%, not 50%.
How do I find the original price?
Divide the sale price by one minus the discount rate. $60 after 25% off came from 60 ÷ 0.75 = $80.
Is buy-one-get-one-free the same as 50% off?
Only per item, and only if you wanted two. BOGOF halves the per-unit price but doubles the quantity you must buy; 50% off applies to a single item.
Is tax charged before or after the discount?
After. US sales tax applies to the discounted price you actually pay, so a coupon reduces the tax too.
What discount equals a "half price" claim?
50% exactly. Watch for "up to 50% off", which only guarantees that at least one item in the range is half price.
How do I compare two different offers?
Reduce both to a final price per unit for the quantity you actually want. A 40% single-item discount usually beats buy-two-get-one-free if you only need one.
Does the calculator handle a dollar-amount discount?
Yes — enter the saving as an amount instead of a percentage, and the effective discount rate is shown.
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