Discount Calculator
Apply one or two sequential discounts, add a tax assumption, and see the cost for several items.
Last updated: November 4, 2026
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Quick summary: Apply one or two sequential discounts, add a tax assumption, and see the cost for several items.
Read the complete guide
Updated reference sections in this guide are in English.
From sticker price to checkout total
Enter the original price of one item and the number of identical items. Enter the first discount, followed by an optional second discount. Set the second discount to 0 if only one applies. The tax field is a rate you supply; it is applied to the discounted subtotal in this model. Select the same currency as the prices you entered. Changing the currency only changes the display label.
Why discounts must be applied in sequence
Subtotal = discounted unit price × quantity
Tax = subtotal × tax rate ÷ 100
Final total = subtotal + tax
The second discount is calculated from the reduced price, not from the sticker price. The effective discount is 1 minus the product of the two remaining-price factors. Savings are reported before tax so that a price reduction is not mixed with a tax assumption.
A complete checkout example
Two items with 20% off, then another 10% off
Each item starts at 100. The first discount leaves 80, and the second leaves 72. For two items, the subtotal is 144. A 5% tax assumption adds 7.20, giving a total of 151.20. The pre-tax saving is 56, and the combined discount is 28%.
Adding the advertised percentages would suggest 30% off, which would produce an incorrect unit price of 70. The order of two percentage-only discounts does not change the final result, but fixed-amount coupons can behave differently and are outside this form.
Check this scenario in the calculator:
- Original unit price
- 100
- Quantity
- 2
- First discount (%)
- 20
- Second discount (%)
- 10
- Tax after discounts (%)
- 5
- Currency (display only)
- USD — US dollar
What to check on the receipt
Confirm that both discounts apply to the same items and that neither has a cap or a minimum-spend rule. Compare unit prices when package sizes differ. If the store rounds each item or each discount separately, its receipt can differ by a small amount from this tool, which keeps intermediate precision and rounds the displayed amounts.
Tax and promotion limits
This is an arithmetic model, not a determination of local tax rules. Some promotions, shipping charges, exemptions and tax-inclusive prices require different treatment. Enter a tax-exclusive starting price for the model shown here. Shipping, service charges, loyalty points, fixed-value coupons and cash-back rewards are not included. Discounts must be from 0% to 100%; quantity must be a positive whole number.
Discount questions
How do I model a single discount?
Enter that discount in the first field and put 0 in the second field.
Does 100% off produce a negative price?
No. A 100% discount leaves a zero discounted subtotal and zero tax under this model.
Are the prices fetched from a shop?
No. You provide all prices, discounts and the tax assumption. No product or market-price database is used.