Costing worked example

Break-Even Quantity with fixed cost of 45,000 $: a worked example

What does the result look like when fixed cost reaches 45,000 $? The full calculation is worked below with real intermediate numbers. Use before launching a product, tool, or quoted program.

The inputs for this scenario

  • Fixed cost: 45,000 $ (raised for this scenario; the documented default is 18,000)
  • Variable cost per unit: 12.5 $ (unchanged)
  • Selling price per unit: 21 $ (unchanged)
  • Target volume: 3,000 units (unchanged)

Working through the calculation

  • Applying the documented formula (Contribution margin = price − variable cost) to the inputs above produces each figure below.
  • At this operating point the engine returns 5,294 units for break-even quantity, the number this scenario is built around.
  • At this operating point the engine returns 8.5 $ / unit for contribution margin.
  • At this operating point the engine returns 111,176 $ for break-even revenue.
  • At this operating point the engine returns -19,500 $ for profit at target.

How this compares with the baseline

  • Against the tool's baseline example, where fixed cost sits at 18,000 $ and the headline result is 2,118 units, this scenario comes in 150% above the baseline at 5,294 units.
  • A figure at this level is achievable when fixed cost is genuinely sustained, not just peaked for a shift. It assumes a single price and constant per-unit variable cost; volume discounts, scrap creep, or a product mix break the straight-line model.

Results at a glance

  • Break-even quantity: 5,294 units (headline result)
  • Contribution margin: 8.5 $ / unit
  • Break-even revenue: 111,176 $
  • Profit at target: -19,500 $

Run it with your numbers

  • Every input above is editable in the live Break-Even Quantity calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.