Trace how the mix changes composite break-even
| Unit-mix case | Weighted contribution | Fixed cost ÷ weighted contribution | Composite threshold |
|---|---|---|---|
| 60% A / 40% B | (30 × 0.60) + (12 × 0.40) = 22.80 CU | 4,560 ÷ 22.80 = 200 | 200 composite units |
| 40% A / 60% B | (30 × 0.40) + (12 × 0.60) = 19.20 CU | 4,560 ÷ 19.20 = 237.5 | 238 composite units, rounded up |
The lower-contribution mix needs 38 more composite units under these assumptions. Recalculate with the Weighted Multi-product Break-even Planner whenever the expected unit mix, contribution or fixed-cost boundary changes.
Define the composite unit before doing the maths
A weighted break-even result is only interpretable when the mix is defined in units. A 60/40 unit mix means that every 100 composite units contain 60 units of A and 40 units of B. Revenue share is not interchangeable with unit share when products have different prices.
Use a mix supported by a stated scenario—recent matched sales, a constrained production plan or a deliberate offer mix. Do not average separate product break-even results, because shared fixed costs would be recovered more than once or allocated without an explicit basis.
Calculate a weighted threshold
Prerequisites, sequence and checkpoints
- Define a representative unit mix whose weights sum to 100%. (not complete)
- Calculate price minus variable cost for every product on one basis. (not complete)
- Multiply each unit contribution by its mix weight and sum the weighted rows. (not complete)
- Divide fixed costs by weighted contribution and round composite units upward. (not complete)
- Translate the composite result back to product units and test a changed mix. (not complete)
Expose the weighted contribution rows
Weighted unit contribution = sum(unit contribution x unit-mix weight); break-even composite units = fixed costs / weighted unit contribution
- unit contribution
- selling price minus variable unit cost for each product (CU per unit) — user-entered scenario
- unit-mix weight
- expected share of composite units; all weights must total 100% (percentage) — user-entered scenario
- fixed costs
- fixed costs for the same declared period (CU per period) — user-entered scenario
Round the operational composite-unit threshold upward, then translate it back into product units using the stated mix.
| Product | Unit contribution and weight | Weighted contribution |
|---|---|---|
| A | 30 CU × 60% | 18 CU |
| B | 50 CU × 40% | 20 CU |
| Composite unit | Weights total 100% | 38 CU |
Calculate and stress-test the mix
Reproducible user scenario
Fictional monthly, tax-excluded scenario with 3,800 CU fixed costs.
| Step | Input or arithmetic | Decision meaning |
|---|---|---|
| Base mix | 3,800 ÷ 38 = 100 composite units | 60 A units and 40 B units |
| Changed mix | (30 × 80%) + (50 × 20%) = 34 CU | Lower weighted contribution |
| Changed threshold | 3,800 ÷ 34 = 111.76; round up to 112 composite units | Mix shift raises required units under the model |
Check whether the changed threshold is operationally possible
The changed 80/20 mix lowers weighted contribution from 38 CU to 34 CU and raises the rounded threshold from 100 to 112 composite units. At that mix, the operational translation is approximately 90 A units and 22 B units after whole-unit planning. Recalculate from the exact planned product counts if that rounding changes the mix materially.
Three decisions after the arithmetic
- Capacity: can the business produce, stock or deliver the implied units of A and B in the stated period? (not complete)
- Mix evidence: is 80/20 a credible planning case or merely the current result of a temporary stock-out? (not complete)
- Contribution repair: if the threshold is infeasible, test product cost, price or mix separately rather than assuming more volume will appear. (not complete)
- Step costs: create another scenario if the added units trigger new staff, equipment, space or fulfilment tiers. (not complete)
Limitations, evidence and next action
Use the calculation owner for the next step
- Weighted Multi-product Break-even Planner
Calculate break-even for an explicit product mix
Questions and boundaries
- Why round upward?
- A fractional composite unit cannot recover the remaining fixed cost in an operational unit model.
- Does the expected mix predict sales?
- No. It is an entered scenario that must be tested against evidence and capacity.
Sources and scope
- Break-even point — U.S. Small Business Administration: Supports the contribution and break-even structure, not demand or viability forecasts.