Calculator

Contribution Margin & Promotion Impact Calculator

Interactive scenario builder that collects item-level costs, expected lift and cannibalization, and promotion inputs so managers can save and compare promotion scenarios. Includes clear manual formulas and a worked example so teams can validate results and avoid costly pricing mistakes.

Interactive Tool

Contribution Margin & Promotion Impact Calculator

What this tool does

This scenario builder helps you estimate item-level contribution margin and test how a promotion or price change will affect margin, total contribution, and the extra volume needed to break even. Enter your item costs, normal sales, and promotional assumptions. The form saves scenarios so you can compare multiple approaches.

Key formulas (manual)

  1. Contribution margin per unit = Selling price - (Recipe cost + Variable overhead per unit)
  2. Contribution margin % = Contribution margin per unit ÷ Selling price × 100
  3. Incremental contribution from promotional units = Promotional price - (Recipe cost + Variable overhead per unit)
  4. Net new units from promotion = Baseline units × Sales lift % × (1 - Cannibalization %)
  5. Promotion incremental contribution (total) = Net new units × Incremental contribution per unit - Additional promo costs
  6. Break-even extra units = (Loss in contribution from discount + Additional promo costs) ÷ (Incremental contribution per promo unit)

Worked example

Baseline selling price = $12.00; recipe cost = $3.00; variable overhead allocation = $1.00 → contribution/unit = $12.00 - ($3.00 + $1.00) = $8.00 (66.7%).

Promo price = $9.00 → promo contribution/unit = $9.00 - ($3.00 + $1.00) = $5.00 (55.6%). Loss per unit during promo = $3.00. If baseline weekly units = 200 and you expect a 30% lift with 20% cannibalization: net new units = 200 × 0.30 × (1 - 0.20) = 48 new units. Incremental contribution from those new units = 48 × $5.00 = $240. If you incur $150 additional promo costs, net incremental contribution = $240 - $150 = $90 (positive). To recover a $600 total loss at promo price vs baseline, you'd need 600 ÷ 5 = 120 extra promo units (at $5 incremental contribution/unit).

Use the fields below to capture your scenario. After saving, you can run multiple scenarios and compare results manually or export data for spreadsheet analysis.

Give this scenario a short name (e.g., 'Spicy Burger - Summer Promo').
Enter the regular menu price (use your currency). Example: 12.50
If running a discount or limited-time price, enter it here. Leave blank if unchanged.
All direct ingredient and packaging costs per serving. Do not include labor or fixed overhead here.
Portion of variable costs (credit card fees, packaging, utilities proportion, extra labor per item) allocated per serving. Use your typical allocation method.
Typical weekly sales volume for this item before the promotion. Use POS data for accuracy.
Enter the percent increase you expect during the promotion (e.g., 30 for +30%).
Percent of promotional sales that will replace other sales rather than being net new (e.g., 20 = 20%).
Length of the promotion in weeks.
Total extra costs for the promotion (signage, marketing, extra staffing). Enter 0 if none.
Capture assumptions such as dayparts affected, channel (in-store vs delivery), or special conditions.
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