DISCOUNT CALCULATOR
$80.00 × 25% = $20.00 savings. Final price $60.00. Two-decimal rounding. Two discounts in sequence don’t add up — 50% off then 20% off is 60% off, not 70%, because the second discount comes off the already-reduced price.
Updated May 2026 · Built by Lukáš, an architect in Prague.
Formula, assumptions, rounding & limitations
Formula
savings = price × (discount ÷ 100)final price = price − savingsfinal price = price × (1 − discount ÷ 100)(equivalent)
Assumptions
- Discount is applied to the original (pre-tax) price you enter.
- Stacked discounts (e.g. 50% off then 20% off) are not 70% off — run them one at a time, since the second discount applies to the already-reduced price.
- Both decimal comma (12,5) and decimal point (12.5) are accepted.
Rounding
- Final price and savings are rounded to 2 decimal places for display.
Limitations
- Sales tax is not added — use the Sales Tax Calculator for the next step.
- Shipping, minimum-order rules, and coupon eligibility are not modelled.
- Buy-one-get-one and quantity-based promotions need to be entered as their effective per-item percentage.
If something is “50% off” and I have a 20% coupon, what’s the final discount?
60%, not 70%. The 20% comes off the already-discounted price. $100 → 50% off → $50 → 20% off → $40. Final price is 40% of original = 60% discount total.
How do I find the original price from a sale price?
Original = final ÷ (1 − discount/100). If you paid $60 with 25% off, original was $60 ÷ 0.75 = $80. Useful for verifying the discount actually matches what’s claimed.
Is “buy one get one free” the same as 50% off?
Yes, mathematically — assuming you wanted both items. If you only wanted one, BOGO is 0% off (you’re paying full price for the one you wanted). 50% off is straightforwardly cheaper for any quantity.
Do these calculations include sales tax?
No. Discount is applied to the pre-tax price; tax is then added to the discounted total. Use the Sales Tax Calculator for the next step.