How do you calculate break-even units in a spreadsheet?
Short answer
Subtract variable unit cost from selling price to get unit contribution, then divide period fixed costs by that positive contribution. Round up when only whole units can be sold. With $12,000 fixed cost, an $80 price, and $50 variable cost, contribution is $30 and break-even volume is 400 units. Nonpositive contribution has no finite break-even volume in this model.
With contribution in F11 and fixed cost in D11, use =IF(F11<=0,"",ROUNDUP(D11/F11,0)). The SBA break-even guidance describes the underlying relationship.
What period should break-even fixed costs cover?
Use the same period as the planned sales volume. Monthly fixed costs divided by contribution produce a monthly break-even volume, not an annual volume. Shared fixed costs and a changing product mix need additional assumptions.