How to use this calculator
Enter the original price, percentage off and an optional tax rate. The calculator subtracts the discount first and applies tax to the discounted subtotal. Leave tax at zero for a sale-price-only result. Use any currency consistently: the calculator does not convert currencies or assume tax rules for your location.
Formula
Original price × (1 − Percentage ÷ 100) × (1 + Tax after discount ÷ 100)
Worked example
A price of 200 with 15% off saves 30, leaving 170. At 8% tax on the discounted amount, tax is 13.60 and the final price is 183.60. The saving shown is the pre-tax discount amount.
Assumptions and limitations
This models one discount and one tax rate on the discounted subtotal. It excludes shipping, coupons applied in a different order, tax-inclusive pricing and merchant-specific rounding. A 100% discount gives a zero subtotal. Confirm checkout totals with the seller.
Frequently asked questions
Do two 20% discounts make 40% off?
No. Applied one after the other, 100 becomes 80 and then 64: the combined discount is 36%. This tool models one discount, so enter 36% for that combined effect.
How precise are these results?
Calculations use ordinary floating-point arithmetic. Results show up to six decimal places; very small nonzero values use scientific notation. They are estimates for everyday arithmetic, not arbitrary-precision accounting.
Can I use decimals and negative numbers?
Yes where the input allows them. Percentage change requires a nonnegative starting value; difference uses nonnegative values; discount requires a nonnegative price and a rate between 0% and 100%.
Keep the same units for both values. Amounts have no assumed currency.