How to calculate a discount
Multiply the original price by the discount percentage to get your savings, then subtract that from the original price for the final sale price.
Stacking discounts
- Two 20% discounts are not 40% off — they apply one after another (36% total).
- Always check whether a coupon applies before or after tax.
Frequently asked questions
Does this handle 'buy one get one'?
Not directly — for BOGO, enter an effective discount (e.g. 50% off two items).
Can I find the original price from the sale price?
If you know the discount %, divide the sale price by (1 − discount/100).