What this calculator answers
Feature Tradeoff estimates how many additional units must be sold to recover the economic effect of adding a product feature. It combines the feature’s per-unit cost, any fixed development or tooling expense, the original unit volume, price, and profit assumptions. The result is a break-even threshold for discussion—not a prediction that the extra sales will occur.
How the tradeoff works
A feature can reduce profit on every unit already expected to sell and may also require a one-time investment. Those losses must be recovered through contribution from incremental units. If the new profit per extra unit is zero or negative, additional volume cannot create a mathematical break-even under the entered assumptions.
Example
Suppose a feature adds $2 to the variable cost of 10,000 expected units and requires $8,000 in fixed engineering expense. The calculator first measures the profit reduction on the initial volume, adds the fixed expense, and then divides that total by the contribution generated by each truly incremental unit. This makes the volume consequence visible before a pricing or roadmap commitment.
Questions the number cannot answer
Incremental sales must be sales that would not otherwise have happened. The calculation does not estimate customer demand, competitive response, support cost, warranty exposure, cannibalization, schedule risk, or strategic value. Run conservative, expected, and optimistic scenarios and document the source of each assumption before using the result in a business decision.
Common questions
Should development cost be spread across the original forecast? Enter the fixed cost and let the model include it in the break-even requirement rather than hiding it in an arbitrary unit cost. What if the feature prevents lost sales? Model retained volume as a separate scenario because avoiding a decline differs from generating new demand. Should support and warranty be included? Include credible incremental costs when they change the contribution created by each extra unit.
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