Discount Calculator
Enter the original price and discount percent to get the sale price, the dollars you save, and the true effective discount.
A discount calculator that also handles stacked coupons: enter the original price, the main discount, and an optional second percent-off, and it applies them the way stores do — sequentially — showing the final sale price, total savings, and the effective discount percentage.
How to use this calculator
- Step 1: Enter the original price, e.g. 120.
- Step 2: Enter the discount percent, e.g. 30.
- Step 3: Optionally enter a second stacked discount, e.g. 10 for an extra coupon.
- Step 4: Click Calculate and read the sale price, total savings, and effective discount.
The formula
sale = price × (1 − d1/100) × (1 − d2/100); effective % = savings / price × 100
Worked example
A $120 jacket at 30% off costs $84.00 — you save $36.00. Stack an extra 10% and the price drops to $75.60: $44.40 total savings, a 37% effective discount (not 40%, because stacked discounts multiply).
Frequently Asked Questions
How do stacked discounts work?
They apply sequentially, not additively. A 30% discount followed by an extra 10% means the second 10% comes off the already-reduced price: $120 becomes $84, then $75.60. The true total is 37% off, not 40%. Stores always stack this way, so adding the percentages overstates your savings.
What is the effective discount percentage?
It's your total savings divided by the original price. With stacked discounts this is the honest single number describing the deal, and it's always a bit less than the sum of the two percentages. Use it to compare a stacked offer against a single straight discount.
How do I find the original price from a sale price?
Divide the sale price by (1 − discount as a decimal). If something costs $75.60 after 37% off, the original was $75.60 / 0.63 = $120. This is useful for checking whether a 'was $X' claim on a price tag is real.
Should I apply the bigger discount first?
It doesn't matter — multiplication commutes, so 30% then 10% gives exactly the same final price as 10% then 30%. The order only matters psychologically, not mathematically.
Does sales tax apply before or after the discount?
After, in almost every state: tax is computed on the discounted sale price, not the original. Manufacturer rebates are the main exception — some states tax the pre-rebate price. Compute your sale price here first, then run it through the sales tax calculator.