Profit planning scaffold

Break-Even / Contribution Margin

Model fixed vs variable costs to understand how many guests or items you need to sell to cover expenses.

Scenario inputs

Plug in menu price, variable cost, and fixed expenses for the period.

Menu price (per item)

Variable cost

Fixed costs

Break-even snapshot

Contribution margin: $11.50
Contribution margin %: 63.9%
Units to break-even: 1087.0
Revenue to break-even: $19,565.22

Warnings & notes

Looks good. Try flexing price or variable cost to see how contribution margin reacts.

Formula reference

Units break-even = Fixed Costs ÷ (Price − Variable Cost).

Contribution margin ratio = (Sales − Variable Cost) ÷ Sales.

Edge Cases to Cover

If price is less than or equal to variable cost, surface an "impossible" warning and disable results.
Handle zero or negative fixed costs gracefully for seasonal pop-ups.
Ensure contribution margin ratio stays within 0-100% even with odd inputs.

What's next

Contribution margin scenarios with price sliders and variable cost sensitivity.
Autosave wiring for codex.breakeven.v1 plus regression tests.
Playwright flows covering per-item vs per-guest toggles.

Acceptance Tests

Replicate the SBA break-even example values for both units and revenue targets.
Switch between per-item and per-guest mode and confirm formulas adjust correctly.
Persist the last scenario to codex.breakeven.v1 and restore on reload.

Calculator drafts will persist locally using the codex.breakeven.v1 cookie once the storage harness ships. Clear your browser data to remove saved scenarios.