Discount Cost Calculator
How many more sales does a discount need to be worth it?
Also known as: Discount & margin erosion calculator
Product and promo
Extra units needed to break even
- Units a month to match today
- 629
- Profit per unit: before / after
- ₹1,099 / ₹700
- Gross profit a month today
- ₹4,39,780
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How it works
How does the Discount Cost Calculator work?
To keep the same gross profit after a discount, unit sales must rise by discount ÷ (margin − discount). A 20% discount on a 40% margin needs 100% more units.
- Margin and discount are both percentages of the list price.
- Break-even lift = d ÷ (m − d); if the discount is at or above the margin, every sale loses money.
- Ad spend for the promo comes on top; include it in your margin if it scales with units.
Worked example
₹1,999 product at 55% margin earns ₹1,099 a unit. At 20% off it earns ₹700, so you need 0.20 ÷ (0.55 − 0.20) = 57% more units (629 instead of 400) to make the same gross profit.
Limits
Ignores customers who'd have bought at full price, and any halo on other products.
Related tools
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This free calculation runs locally and is a planning aid, not financial, tax or legal advice. Nothing you type leaves this page unless you choose to save it.