Work out a sale price and savings from a percent-off, fixed-amount, stacked-discount or buy-X-get-Y offer. You can also find the discount percentage from two known prices and model a stated tax rate.
Discount Calculator
Find the sale price and exactly how much you save. Choose a discount type, enter the numbers, and add tax if you need to.
Use the discount mode that matches the offer
- Choose the offer type from “What type of discount?”
- Enter the original price and the values requested for that mode.
- Choose no tax, add tax, or tax already included. Enter a rate only when it applies to your example.
- Click Calculate and compare the sale price, saving, effective discount and final amount.
The currency selector changes the label and formatting. It does not convert money using exchange rates. Use nonnegative prices, discount rates from 0% to 100%, and positive whole-item quantities for shopping comparisons.
Percent off: calculate the saving and sale price
saving = original price × discount % ÷ 100sale price = original price − saving
On an 80 item with 25% off, the saving is 80 × 0.25 = 20, so the sale price is 60. On a 250 item with 30% off, the saving is 75 and the sale price is 250 − 75 = 175.
A quick reasonableness check is the percentage you still pay: 25% off leaves 75% of the original price, so 80 × 0.75 = 60.
Fixed amount off
For a fixed coupon, subtract the eligible amount from the original price. A 15 discount on a 75 item leaves 60, equivalent to 15 ÷ 75 × 100 = 20% off.
The calculator caps a fixed discount at the original price. A larger coupon therefore does not produce a negative price here. Actual coupon rules may impose a minimum spend, exclude products or decline an offer altogether.
Find the discount percentage from two prices
Select “I know the sale price — find the discount” when both prices are known:
discount % = (original price − sale price) ÷ original price × 100
A reduction from 120 to 90 saves 30, giving 30 ÷ 120 × 100 = 25% off. This checks the relationship between those two prices; it does not verify the seller’s price history.
If you know only a sale price and a percentage discount, recover the original manually with original = sale price ÷ (1 − discount % ÷ 100). For example, 120 after 20% off came from 120 ÷ 0.80 = 150. Use the Percentage Calculator for that missing-total calculation.
Stacked discounts: apply them one after another
sale price = original × (1 − first % ÷ 100) × (1 − second % ÷ 100)
Starting at 100, 20% off leaves 80. Another 10% off that reduced price removes 8, leaving 72. The saving is 28, so the effective discount is 28%, not 30%.
Reversing two percentage discounts produces the same mathematical result before rounding. Retailer rounding, eligibility conditions and mixing a fixed coupon with a percentage discount can change the checkout amount.
Buy X, get Y free
This mode assumes every item in the group has the same entered unit price. It compares the normal value of X + Y items with the cost of paying for X items:
effective discount % = Y ÷ (X + Y) × 100
With buy 2, get 1 free at 12 per item, three items normally cost 36. You pay 24 and save 12: an effective discount of about 33.33%. A buy-1-get-1-free offer on equal-price items gives 50% off the two-item group.
Do not use this equal-price result for an offer where the cheapest of differently priced items is free. The calculator also does not determine whether you qualify for the promotion.
Adding tax versus tax already included
Add tax: the model applies the entered rate to the discounted sale price. A sale price of 60 with 10% tax produces 6 tax and a final amount of 66.
Tax already included: the amount you pay stays the same. With an included-tax total of 66 at 10%, the pretax portion is 66 ÷ 1.10 = 60 and the tax portion is 6.
Use whichever model matches the actual price display and transaction rules. This calculator does not identify your location, fetch tax rates, add shipping or determine how a jurisdiction treats coupons.
Questions about discounts
Does 20% off followed by 20% more return to the original price?
No. Starting with 100, 20% off gives 80, and adding 20% of 80 gives 96. Each percentage uses the amount at that step.
Why can the checkout total differ?
Check offer eligibility, shipping, fees, the taxable amount and rounding. The display rounds money to two decimal places; a merchant may round at a different stage or use a different rule.
Can the tool prove that a deal is good value?
It checks the supplied numbers. Compare the final price, item size and seller’s terms with other offers before deciding whether a purchase is worthwhile.
What if the original price is zero?
A meaningful percentage saving cannot be calculated by dividing by a zero original price. Compare absolute prices instead and correct an accidental zero input before using a displayed percentage.
Related guide
How to calculate stacked discounts explains why successive reductions are multiplied. Check the offer’s actual sequence and conditions before applying the example to a purchase.