Formulas
| Measure | Formula |
|---|---|
| Contribution per unit | Selling price − variable cost per unit |
| Contribution margin ratio | Contribution ÷ selling price |
| Break-even units | Fixed costs ÷ contribution per unit |
| Break-even revenue | Fixed costs ÷ contribution margin ratio |
| Units for target profit | (Fixed costs + target profit) ÷ contribution per unit |
| Margin of safety | (Actual sales − break-even sales) ÷ actual sales |
Getting the inputs right
- Fixed: rent, salaries, software subscriptions, loan EMIs, insurance
- Variable: raw material, packaging, shipping, payment gateway and marketplace fees, commissions
- Use prices net of GST — GST collected isn't revenue
- Rerun it whenever prices, costs or the team change
Worked example: D2C product brand
- 1Fixed costs ₹6,00,000 a month; selling price ₹1,000 (excluding GST); variable cost ₹600.
- 2Contribution = ₹400 per unit; ratio = 40%.
- 3Break-even = ₹6,00,000 ÷ ₹400 = 1,500 units, or ₹15 lakh revenue a month.
Selling 2,000 units gives ₹2 lakh profit and a 25% margin of safety.

