Extra sales needed to recover profit after a discount
Required volume multiplier = original margin fraction ÷ (original margin fraction − discount fraction). At a 40% pre-discount contribution margin, a 10% price discount requires 33.33% more units to preserve contribution.
Extra sales needed to recover profit after a discount
| Original contribution margin | Price discount | Contribution per unit remaining | Required unit increase |
|---|---|---|---|
| 20.00% | 5.00% | 75.00% of original | 33.33% |
| 20.00% | 10.00% | 50.00% of original | 100.00% |
| 30.00% | 10.00% | 66.67% of original | 50.00% |
| 40.00% | 10.00% | 75.00% of original | 33.33% |
| 40.00% | 20.00% | 50.00% of original | 100.00% |
| 50.00% | 10.00% | 80.00% of original | 25.00% |
| 50.00% | 20.00% | 60.00% of original | 66.67% |
| 60.00% | 15.00% | 75.00% of original | 33.33% |
Formula & method
New contribution per original price unit = m − d
Required volume multiplier = m ÷ (m − d)
Extra units% = (multiplier − 1) × 100Both the original contribution margin and discount must be fractions of the original selling price. The calculation assumes variable cost per unit does not fall when the price falls. Multiply the new unit contribution by the required volume to recover the original total contribution.
Recovering revenue is a different target and usually needs a smaller increase. Capacity limits, extra labour, fulfillment fees and new customers’ behaviour can invalidate the constant-cost assumption. Use this table to expose the arithmetic trade-off, not to forecast demand.
Worked example
A product sells for 100 and has variable cost 60. Discounting the price to 90 lowers unit contribution from 40 to 30. Selling 400 units instead of 300 restores contribution to 12,000: a 33.33% unit increase.
What can change the answer
When discount is at least the original margin, no finite higher volume restores positive original contribution under this model. Additional fixed costs or changing unit costs require a revised model.
Sources & definitions
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Continue with a related task
Gross Margin Calculator
Gross margin is revenue minus included cost of goods, divided by revenue, multiplied by 100. Revenue of 1,000 and cost of 650 gives a gross profit of 350 and margin of 35%.
Markup Calculator
Markup equals selling price minus cost, divided by cost, multiplied by 100. Buying at 80 and selling at 100 gives a 25% markup, while the margin is 20%.
Target Margin Selling Price Calculator
Required selling price equals unit cost divided by one minus the target-margin fraction. A cost of 60 and a 40% target margin gives a price of 100.
Unit Price Calculator
Unit price equals total package price divided by quantity. A package costing 18 for 12 equivalent units costs 1.50 per unit.