Calculators
How to Calculate Discount and Sale Price
AllinOne Editorial · Published 2026-09-16
“20% off” means you pay 80%. Reconstructing the original from a sale tag is a different formula.
Shop discounts are percentages of the original price. People mix up three questions: what do I pay, what was the original, and what percent is this markdown?
The three formulas
- Sale = original × (1 − percent/100).
- Original = sale ÷ (1 − percent/100).
- Percent off = (original − sale) ÷ original × 100.
Worked example
20% off 2,499 is a 499.80 saving and a 1,999.20 sale price. If a tag shows 1,999 at 20% off, the implied original is 2,498.75 — rounding on printed stickers often differs by a rupee or two.
Stacked discounts (10% then 10%) are not 20%. Apply them in order, or convert each to a multiplier and multiply.
Frequently asked questions
Does this include sales tax?+
No. It only applies a percent to the prices you enter.
Can the discount be 100%?+
A 100% discount makes the sale price 0. You cannot reconstruct an original price from a free item.
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