Compute · Assess & Decide · Analysis & Finance

Compute the break-even sales change for a price change

You get the minimum percent (and unit) sales-volume change at which a proposed price change leaves total profit contribution unchanged.

You receive: A pure function that, given a price change and the baseline contribution margin, returns the break-even percent sales change, the break-even unit change, the resulting new contribution margin, and whether the result is economically defined.

Part of Choose Business Model

What's verified: STUD verifies the ARITHMETIC of the break-even formula only: that the function reproduces the book's price-volume trade-off math on held-out inputs and that the declared algebraic invariants hold. STUD does NOT verify that the supplied price change, contribution margin, or baseline units are real or correctly measured; does NOT estimate or predict the actual sales response (the book is explicit that whether realized volume will clear the break-even is a separate qualitative judgment for a sales or product manager); does NOT verify that the market will accept the new price; and does NOT assert anything about fixed-cost recovery or overall product profitability (this is an INCREMENTAL break-even on contribution, not a total break-even). The dollar-sales conversion is reported only when the buyer supplies the percent price change; STUD does not infer it.