How many units until you break even?
Break-even units is how many units you must sell before contribution margin covers your fixed costs. Divide the fixed costs of the period or launch by the contribution margin per unit - price minus the full variable cost of selling one unit - and round up. This calculator returns the units, the revenue they represent, and how many months your current run rate takes to reach them.
Rent, salaries, software and launch one-offs: the costs that do not move with a sale.
What one unit actually sells for after average discount, not the RRP.
Landed COGS (cost plus freight-in plus duty) plus shipping and fulfilment plus payment and platform fees, per unit. Build the landed part with the landed COGS calculator.
Units you sell per month today. Adds a months-to-break-even line; leave it at zero to skip it.
You break even at 625 units: $50,000 of revenue. At 250 units a month that is about 2.5 months away. Every unit past it contributes $32.00 before marketing.
Break-even units at your contribution margin per unit, then shifted ten and twenty percent either way. Computed from your inputs, nothing assumed.
Four inputs, and where to find them
Every number here already exists in your stack. Pull them for the same product and the same window so the answer is internally consistent.
Add up the fixed bet
From the P&L: rent, salaries and software for the period - or, for a launch, the one-offs the launch creates: tooling, photography, the production run's setup. Leave out anything that scales with units sold; that belongs in step 3.
Set the real price per unit
From your store's order data: the SKU's revenue divided by units sold, so average discount is already in it. The RRP flatters the margin before you start.
Build the full variable cost per unit
Landed COGS first - cost plus freight-in plus duty, from supplier invoices and freight bills; the landed COGS calculator builds it line by line. Then add shipping and fulfilment from your 3PL invoice, and payment and platform fees from your processor statement, per unit.
Pull the run rate (optional)
Trailing three months of units for this product from your order export, divided by three. It turns the units answer into the months answer your cash actually cares about.
One division, rounded up
Contribution margin per unit is what one sale leaves after the costs that move with it. Fixed costs do not move with a sale, so the only question is how many contributions it takes to cover them - and you round up, because units sell whole.
Same definitions as The Math: variable cost per unit is landed COGS (cost plus freight-in plus duty) plus shipping and fulfilment plus payment and platform fees, so the margin each unit carries is the margin before marketing. The division only exists while price exceeds variable cost - a unit that loses money cannot buy back a fixed cost at any volume.
Each unit sells for $80.00 and takes $48.00 of variable cost with it, leaving $32.00 of contribution margin per unit.
Fixed costs to cover: $20,000 ÷ $32.00 = 625 units, rounded up to whole units. Those 625 units are $50,000 of revenue at that price. At 250 units a month, break-even lands about 2.5 months in.
These are your live inputs from the calculator above, not a canned example. Change a number up there and this paragraph follows.
The size of the bet, in units
Fixed costs are a bet that enough units will sell to absorb them. This number states that bet in the only denomination that matters: sales your channel actually has to produce.
Green-light with open eyes
Before money is committed, compare break-even units to what the channel has sold in a comparable window. If the floor sits above anything it has ever produced, the launch is priced or costed wrong before it starts - and it is far cheaper to learn that here than in the warehouse.
Price moves the floor fastest
Every dollar of price lands whole in CM per unit while variable cost stands still, so a small price move swings the units number harder than almost any cost saving. Re-run the floor before you set the launch offer, and again before any discount goes sitewide.
The months line is the cash question
Units say how many; the run-rate line says how long your cash is underwater while they sell. A launch that breaks even eventually can still fail in the meantime, and the months line is where that shows up first.
A floor, not the finish line
Because gross-margin launch math flatters everyone
The usual launch napkin divides fixed costs by price minus product cost and stops there. But shipping, fulfilment and payment fees leave with every unit too, so that division runs on a margin that does not exist - and understates break-even badly.
Dividing by the full variable cost per unit - landed COGS, shipping and fulfilment, payment and platform fees, the same step-down as The Math - prices the floor in real units, and it is the version your ledger will eventually agree with.
Never when ads have to sell the units
This floor assumes the units sell themselves. The moment demand is bought - ads, affiliates, promos - every unit carries an acquisition cost this math ignores, so the true break-even sits higher than the number above.
What we do instead: put CAC per unit into the variable cost and re-run it as a sell-through break-even. CM per unit shrinks by the cost of winning each sale, and the units number answers the question a launch actually has to answer: how many units must sell at the acquisition cost you will really pay.
Break-even, on the efficiency frontier
This page runs one napkin division. Blufire S11 Planning & Forecasting carries payback and breakeven on the efficiency frontier, and S2 gives the real CM per unit inputs - so the floor you plan against moves with what each unit actually contributes, not a one-off estimate.
The protocol
Run it with the launch one-offs in fixed costs and the offer's real price after discount. Write the units number next to what the channel sold in a comparable window - that comparison is the go or no-go.
Recompute on the trailing month's fixed costs and current variable costs. Freight, fees and software line items all drift, and the floor drifts with them. File the number: the trend is the point.
Re-run with the new price. Price moves CM per unit dollar for dollar, so the units number swings harder than any cost line - check the floor before the offer goes live.
The months line stretches past what your cash can fund, or break-even units pass anything the channel has sold in a comparable window. Reprice, cut variable cost, shrink the fixed bet - or do not launch.
Questions operators ask
Because a fraction of a unit cannot be sold, and at the fraction below the line you are still short. If the division gives 624.3, unit 624 still leaves a sliver of fixed cost uncovered and unit 625 is the first one past it. Rounding down would declare break-even one sale too early.
Anything that does not move with a sale: rent, salaries, software, plus the one-offs of a launch such as tooling or a photoshoot. If a cost scales with units sold - product cost, freight, fulfilment, fees - it belongs in variable cost per unit instead, where it lowers the margin every unit carries.
Everything one sale takes with it: landed COGS (cost plus freight-in plus duty), shipping and fulfilment, and payment and platform fees. Stopping at the product cost alone, the way gross-margin math does, makes the margin read fatter than it is and understates break-even badly.
Yes, whenever the units need paid acquisition to sell. This calculator's floor covers the product and its delivery only, so it quietly assumes demand shows up free. Add your acquisition cost per unit into variable cost per unit and re-run it for a sell-through break-even - the honest version when ads are doing the selling.
Yes - fixed costs divided by the contribution margin ratio gives the same line by another route. This page derives it from the rounded-up unit count instead, break-even units times price, so the revenue figure always matches a sellable whole number of units rather than sitting a fraction of a unit below it.
Yes - use a period's fixed costs and swap units for orders: price per unit becomes average revenue per order, and variable cost per unit becomes the per-order step-down of discounts, landed COGS, shipping and fulfilment, and fees. The contribution margin calculator builds that per-order number.