Two directions, one tool
Most discount calculators go one way: price and percentage in, sale price out. Sellers usually need the other direction too — 'the competitor sells at 62 and we sell at 79, what discount does that imply?' Enter both prices and the tool computes the gap as a percentage.
The margin cost of discounting
A discount comes straight out of profit, not revenue. On a 40% gross margin, a 20% discount removes half your gross profit; a 30% discount leaves almost nothing. That is why sitewide sales feel good and close stores: volume rarely doubles to compensate.
Discounting that does not destroy margin
- Bundle instead of cutting — raise AOV while protecting unit price
- Discount the slow SKU, not the hero product
- Use free shipping thresholds rather than price cuts
- Time-box it: permanent discounts become the real price
Legal note
In the US and EU, a 'was' price must be genuine — former prices need to have been actually charged for a meaningful period. Fake reference prices are a regulatory risk, not just a marketing choice.
Frequently Asked Questions
How do I calculate a discount backwards?
Discount % = (original − sale) ÷ original × 100. Enter both prices above.
Does a 20% discount need 25% more volume?
Yes, at the same margin — that is the arithmetic trap of discounting.
Can I stack discounts?
Multiply the multipliers: 20% then 10% is 0.8 × 0.9 = 28% off, not 30%.
Assumptions & disclaimer
Results are estimates for planning. Fee schedules, tax brackets and deduction limits change; confirm current figures with the marketplace, the IRS or a qualified accountant before making decisions. Nothing here is financial, tax or legal advice.
Privacy & Your Data
BizCalcTool runs entirely in your browser. The figures you enter are never uploaded, stored or shared — there is no backend to send them to.