Product Bundle Pricing Calculator
What a bundle discount costs in margin and how much extra volume it needs to pay for itself.
A bundle trades margin for volume and average order value.
How the product bundle pricing calculator works
A bundle trades margin for volume and average order value. The discount comes straight off contribution, so the volume lift needed is larger than the discount looks.
The rule is the same as any discount: at a 40% contribution margin, a 15% discount needs a 60% volume increase to hold contribution flat. This computes that threshold and shows whether the observed lift clears it.
Formula: required lift = d / (m − d) where d is the discount share of price
Worked examples
| Inputs | Bundle margin | Note |
|---|---|---|
| Three items at 100 list, 85 bundle | 48.24% | needs a 34% lift |
| A deeper discount | 37.14% | needs far more volume |
| A shallow discount | 53.68% | easy to clear |
FAQFrequently asked questions
How much volume does a discount need?
More than the discount. At a 40% contribution margin a 15% discount needs about a 60% volume lift to hold contribution flat.
Why is the required lift so much larger than the discount?
Because the discount comes entirely out of contribution, not out of revenue. Cutting a 41 contribution to 26 means you need 58% more units.
Do bundles always cannibalise?
Often. If customers who would have bought all three items anyway now buy the bundle, the discount is pure margin loss with no lift at all.
What makes a bundle work?
Items that are complementary but not usually bought together, so the bundle creates a sale that would not otherwise happen.
Should I bundle slow-moving stock?
It clears inventory, which has its own value. Just be honest that the contribution comparison is against zero, not against full price.
Where these figures come from
- APICS / ASCM — inventory management terminology — the turnover, safety stock and reorder point definitions used here
- UK Competition and Markets Authority — the UK consumer protection regulator
Last checked: September 2026. These are standard retail and inventory-management definitions.