UtilibyWritten by the Utiliby editorial team · Last updated October 17, 2026 · Rules and formulas reviewed October 2026
What this free discount calculator does
Sales tags, coupon codes and stacked offers can make it hard to know what you will actually pay. A discount calculator works it out. Enter a price and one or two percent discounts, an amount off, a coupon and the sales tax, and this free online tool gives the sale price, the amount saved, the effective discount and the final price including tax, with every step shown.
It also works backwards, finding the original price from a sale price or the percent discount between two prices, and it compares up to three different deals for the same purchase, including buy-one-get-one and buy-N-get-one-free offers. A bar picture shows how much of the original price you pay and how much you save. Nothing you enter leaves your browser.
How to use the discount calculator
- Enter the original price and the quantity.
- Add the discount. Put a percent in the first box, and a second percent for stacked offers.
- Add a fixed amount off, a coupon or sales tax if they apply.
- Read the result and the numbered steps.
- Use the reverse tab to find an original price or a discount percent.
- Use the compare tab to see which of three offers is cheapest.
The discount formulas
The amount off is the original price times the discount rate. The sale price is the original price times (1 minus the discount rate). For $80 with 30% off, the amount off is $24 and the sale price is $56. To add sales tax, multiply the sale price by 1 plus the tax rate: $80 less 25% is $60, and with 8.25% tax you pay $64.95.
| Original | Discount | Sale price | You save |
|---|---|---|---|
| $80 | 25% | $60.00 | $20.00 |
| $80 | 30% then 10% | $50.40 | $29.60 |
| $200 | 30% then 15% | $119.00 | $81.00 |
| $50 | 20% then $10 coupon | $30.00 | $20.00 |
| $59.99 | 25% | $44.99 | $15.00 |
Stacked and successive discounts
Retailers often advertise an extra percentage off sale prices. These do not add up. A 30 percent markdown followed by an extra 15 percent off a $200 item gives $200 x 0.70 x 0.85 = $119.00, a total discount of 40.5 percent rather than 45. The rule is to multiply the remaining fractions: 0.70 x 0.85 = 0.595, so you pay 59.5 percent. The calculator shows each step so you can see how much each layer takes off.
Working backwards from the sale price
To find the original price when you know the sale price and the percent off, divide by the fraction you paid. If a jacket cost $63 after 30 percent off, you paid 70 percent of the original, so the original was 63 / 0.70 = $90. To find the discount between two prices, divide the saving by the original: a drop from $120 to $84 is $36, or 30 percent. These are handy for checking whether a sale is as good as it looks, and for spotting inflated original prices.
Comparing deals fairly
Percent off, money off, buy one get one and multi-buy offers are hard to compare by eye. The compare tab works out what you pay for your quantity under each. Take two $40 items. 30 percent off costs $56. $25 off costs $55. Buy one get one half price costs $60. The $25 off deal is cheapest here, even though 30 percent sounds larger. Change the price or quantity and the winner can flip, which is why a calculation beats a guess.
Discounts, coupons and sales tax
In most places sales tax is charged on the discounted price, but rules vary, and some stores apply manufacturer coupons before tax and store coupons after. The calculator applies percent discounts, then amount off and coupons, then tax. If your store works differently, enter the coupon as a percent or leave tax blank and adjust. Some items such as groceries or clothing may be exempt from tax in your area.
Smart shopping tips
- Check the effective discount rather than the headline percent.
- Compare unit prices as well as discounts.
- Watch for minimum spends and excluded items.
- Track price history to spot fake sales.
- Stack carefully. Not all coupons can be combined.
Accuracy, privacy and responsible use
Results are mathematical estimates. Checkouts may round differently, apply promotions to specific items only or add fees. Check the final total at the till. Nothing you enter leaves your browser.
Related free tools
Use these free online tools together with this one:
- Work out any percent of a number with the percentage calculator.
- Find the best value per ounce or litre with the unit price calculator.
- Share the discounted total fairly with the split bill calculator.
- Work with offers like one third off using the fraction calculator.
- Measure whether a promotion paid off with the marketing ROI calculator.
Frequently asked questions
How do I calculate a discount?
Multiply the original price by the discount percent divided by 100 to get the amount off, then subtract it. 30% off $80 is $80 x 0.30 = $24 off, so the sale price is $56. Or multiply by 0.70 directly.
How do I calculate the sale price after a percent off?
Sale price = original price x (1 - discount/100). For a 25% discount on $80 that is 80 x 0.75 = $60.
What does 30% off then an extra 10% off mean?
The second discount applies to the already reduced price. $80 less 30% is $56, and 10% off that is $50.40. The total discount is 37%, not 40%.
How do I find the original price from the sale price?
Divide the sale price by (1 - discount/100). If you paid $63 after 30% off, the original price was 63 / 0.70 = $90.
How do I find the discount percentage?
Divide the amount saved by the original price and multiply by 100. From $120 to $84 is $36 saved, 36 / 120 = 30%.
How is sales tax added after a discount?
Most places tax the discounted price. Multiply the sale price by (1 + tax rate). $80 less 25% is $60, and with 8.25% tax the total is $64.95.
Is a coupon applied before or after the percent discount?
It depends on the store. This calculator applies percent discounts first, then any amount off and the coupon, then tax. $50 less 20% is $40, less a $10 coupon is $30.
How do I compare two discounts?
Work out the final price for each. A bigger percent is not always better: 20% off $200 saves $40, but $50 off the same price saves more. Use the compare tab to test any mix.
How does buy one get one 50% off work?
You pay full price for the first item and half price for the second, so two $40 items cost $60, which is a 25% discount overall.
How does buy 2 get 1 free work?
For every three items you pay for two. Three $30 items cost $60, a saving of one third, or 33.3%.
Can I calculate a discount on several items?
Yes. Enter the quantity and the calculator shows the total to pay and total saved as well as the per-item figures.
What is the effective discount?
The true overall percentage off the original price after all discounts and coupons are combined. It is what lets you compare unlike offers.
How do I calculate a markdown or clearance price?
It is the same calculation. Enter the original price and the markdown percent. Stack a second markdown for clearance-on-clearance.
Why does my receipt differ slightly?
Stores may round each line, exclude some items from a promotion, apply tax to the original price or cap discounts. Small differences are normal.
Does this work for wholesale or trade discounts?
Yes for simple percent or amount reductions. Chain discounts such as 20% and 10% are handled by stacking them.
Is my data stored or sent anywhere?
No. Everything runs in your browser.
Is this discount calculator free?
Yes. It is free to use online with no sign-up.
Sources and further reading
- Federal Trade Commission, Shopping tips.
- Investopedia, Discount.
- Tax Foundation, State and local sales tax rates.
- Khan Academy, Percent problems.
Sources were consulted in October 2026. Standards and rules can change, so always check the official page for your situation.