Sale price with tax
100 − (100 × 20%) = 80; then 80 × 8% = 6.40 tax.
Savings: 20; price after discount: 80; final price: 86.40.
The tax example assumes the discount reduces the taxable subtotal.
Discount and Tax Calculator
Calculate discount savings, price after discount, sales tax, final price, stacked discounts, and competing offers.
Find the amount saved and price after one discount.
Price results are currency-neutral. Use the same currency for every amount you enter.
Calculate sale price and savings
Use a percentage or fixed-amount discount. Optional tax is applied after the discount.
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Verify whether the discount reduces the taxable amount in your transaction.
Find the discount percentage
Enter the original and advertised sale prices to check the actual percentage off.
Find the original price
Use the current sale price and discount rate to recover the price before the discount.
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The rate must be below 100% because a free item has no unique original price.
Stack percentage discounts
Discounts are applied from left to right. The second percentage is calculated from the price remaining after the first.
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Applied after both discounts.
Compare two discount offers
Each offer can contain one or two sequential percentage discounts. Both use the same original price and optional tax rate.
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Use only when the same rate and taxable-base rule applies to both offers.
Explore More Math Tools
Continue with related pages to compare results and improve decision making.
Discount, Tax and Reverse Calculation Modes
Use Sale price to calculate the original price, discount percentage, savings, discounted subtotal, sales tax, and final price. The other modes find a discount rate, recover an original price, apply two discounts in sequence, or compare competing offers. Amounts are currency-neutral, so use one currency throughout.
Discount and Sales Tax Formulas
The core formula used by this discount and tax calculator is: Discount amount = Original price × (discount rate / 100). Price after discount = Original price − discount amount. Tax amount = Price after discount × (sales tax rate / 100). Final price = Price after discount + tax amount. For stacked offers, apply each percentage to the price left by the previous discount.
The standard calculation applies sales tax after the discount. Actual tax rules can use a different taxable base, so verify whether a coupon or discount reduces taxable value where the transaction occurs. Reverse modes find a missing rate or original price; stacked mode applies reductions sequentially.
For an original price of 100 with 20% off and 8% sales tax, the discount saves 20, the discounted price is 80, tax is 6.40, and the final price is 86.40.
Discount and Tax Examples
Find the original price
72 / (1 - 20%) = 90
Original price: 90
Compare two offers
25% off 100 = 75; 20% then 10% off 100 = 72
The stacked offer costs 3 less and has a 28% effective discount.
Calculate the Final Price After Discount and Tax
- Select Sale price, Discount rate, Original price, Stack discounts, or Compare offers.
- Enter the known prices and percentage or fixed-amount discount requested by that mode.
- Enter the sales tax rate when it applies to the discounted subtotal, or leave it blank for 0%.
- Review the separate savings, tax, and final-price figures or the selected reverse/comparison result.
What the Price Breakdown Shows
- Check an advertised sale price and the amount saved.
- Convert original and sale prices into the actual discount percentage.
- See why sequential discounts cannot simply be added together.
- Separate discount savings from tax instead of treating them as one adjustment.
- Compare promotions using the same price and tax assumptions.
Related Percentage and Tax Calculators
- Try the Add Percentage Calculator for a related calculation.
- Try the Percentage Calculator for a related calculation.
- Read the Discount and Tax Calculator Guide for examples and assumptions.
- Browse the Math Calculators page for more tools.
Related Calculators
Frequently Asked Questions
How do I calculate the price after a discount?
Multiply the original price by the discount percentage divided by 100, then subtract that discount amount from the original price.
Can I compare two offers with stacked discounts?
Yes. Comparison mode applies up to two sequential percentage discounts to each offer and reports both final prices, effective discounts, and the price difference.
Why do 20% off and 10% off equal 28% off?
The second 10% discount applies to the remaining 80%, reducing it by another 8% of the original price. The combined reduction is therefore 20% plus 8%, or 28%.
Does the calculator include sales tax?
Yes. Sale price, stacked discount, and comparison modes can apply a sales tax rate after the discount. A blank tax rate is treated as 0%. Tax rules vary, so verify the taxable base and rate for the transaction.
Is sales tax calculated before or after the discount?
This calculator applies tax after the discount, using the discounted subtotal. Some jurisdictions or promotion types use different rules, so confirm the taxable amount shown on the receipt.