Does my monthly store plan go under fixed costs and the per-order commission under variable cost?
Yes. The monthly plan is a fixed cost because you pay it whether or not you sell, and any commission or fee taken from each order goes into the variable cost per unit. Mixing them up leaves your total spending unchanged, but it makes the break-even look lower than it really is.
The simple test: would I pay it with zero sales?
Take each line of spending and ask whether you would still pay it in a month with no orders at all. The store plan, paid apps, domain and rent all survive a zero-sales month, so they are fixed. Payment gateway charges, per-order platform fees, the product itself and its packaging only appear when something sells, and they grow with every order. Those are variable.
The split matters because the Break-even calculator subtracts the variable cost from the unit price to get the contribution per unit, then divides your fixed costs by it. Put a cost in the wrong box and the contribution moves, and the unit count moves with it.
Worked example: the correct split
- Fixed costs for the month: 3,000, covering the plan, apps and a share of rent.
- Selling price per unit: 120.
- Variable cost per unit: 70, of which 12 is commission and payment fees on the order and the rest is product and packaging.
- Result: a contribution of 50, a break-even of exactly 60 units, and break-even revenue of 7,200.
What happens if the commission is left out
Say you entered a variable cost of 58, the product alone without the commission. The calculator now shows a contribution of 62 and an exact break-even of 48.39, rounded up to 49 units. That is 11 units you believe you do not need to sell.
Worse, if you stop at 49 units trusting that figure, the real contribution is 49 × 50 = 2,450 against 3,000 of fixed costs: a loss of 550 in a month you thought was break-even. A small fee on each order adds up, which is exactly why it belongs to the unit and not to the month.
Costs people often misfile
- Shipping you pay on each order: variable, because it repeats with every order.
- A monthly ad budget you set in advance: fixed for that month. Ads paid per order are variable.
- A flat fee per payment transaction: variable, and if customers buy several units per order, spread it across those units.
Do not rely on generic commission percentages; take the real amounts from your platform and gateway statements. Once the variable cost is right, check the per-unit margin with the Profit margin calculator, or test a price that absorbs the fees with the Selling-price calculator.
Common questions
Does the calculator know which costs are fixed?
No, it uses the numbers exactly as you enter them. The classification is yours, and the easiest test is whether you would pay it with no sales.
My commission is a percentage. How do I enter it?
The variable cost field takes an amount, not a percent. Work the percentage out on your selling price and add the result to the unit cost.
Are my numbers stored anywhere?
No. The calculation runs in your browser and nothing is sent.