234 is the example result. Read it using the units and relationship stated below.
Marketplace Profit uses units sold, selling price per unit, product cost per unit.
Protecting contribution before accepting a price
For marketplace profit, the relationship is Contribution = units × sale price × (1 − fee% ÷ 100) − units × (unit cost + shipping per unit) − ad spend − other costs. The amount depends on the supplied units sold, selling price per unit, rather than a live market price or a value imported from another record. A quote can meet a revenue target and still leave too little to cover delivery. Separate the selling-price denominator from the cost denominator: margin and markup answer different questions. A discount changes contribution even when the supplier cost stays fixed.
What the model includes
Contribution = units × sale price × (1 − fee% ÷ 100) − units × (unit cost + shipping per unit) − ad spend − other costs. A pricing review should retain the supplier cost, sale price and the reason for any allowance. Returns, payment charges, delivery and tax require explicit treatment; they should not disappear inside a percentage labelled profit. Compare the proposed price with the customer agreement and delivery capacity. A mathematically achievable margin does not establish that buyers will accept the offer.
Example with the supplied inputs
Units sold: 20; Selling price per unit: 40; Product cost per unit: 15; Platform fee (%): 12; Shipping per unit: 5; Advertising spend: 50; Other costs: 20. Result: 234. The values are illustrative.
Compare one changed input
Units sold changes from 20 to 22. The result becomes 264.4. All other inputs remain fixed.
Calculation rule
Contribution = units × sale price × (1 − fee% ÷ 100) − units × (unit cost + shipping per unit) − ad spend − other costs.
Inputs and output
| Input | Example value | Entry convention |
|---|---|---|
| Units sold | 20 | Use the source quantity represented by units sold. Keep the counted population fixed and avoid mixing a unit value with a period total. |
| Selling price per unit | 40 | Use selling price per unit on the currency and period basis shown by the formula. Keep gross amounts, net amounts and unit amounts distinct; the page does not fetch a price or exchange rate. |
| Product cost per unit | 15 | Use product cost per unit on the currency and period basis shown by the formula. Keep gross amounts, net amounts and unit amounts distinct; the page does not fetch a price or exchange rate. |
| Platform fee (%) | 12 | Enter platform fee (%) on the percentage scale used in the formula (20 means 20%, not 0.20). Keep its base and reporting period consistent with the other inputs. |
| Shipping per unit | 5 | Use the source quantity represented by shipping per unit. Keep the counted population fixed and avoid mixing a unit value with a period total. |
| Advertising spend | 50 | Use advertising spend on the currency and period basis shown by the formula. Keep gross amounts, net amounts and unit amounts distinct; the page does not fetch a price or exchange rate. |
| Other costs | 20 | Use other costs on the currency and period basis shown by the formula. Keep gross amounts, net amounts and unit amounts distinct; the page does not fetch a price or exchange rate. |
Output: 234 is the example result. Read it using the units and relationship stated below. Use the formula to distinguish a cash amount, count, percentage or ratio.
How to use the page
Collect the inputs
Gather Units sold, Selling price per unit, Product cost per unit. Use one period and the units shown in the form.
Run the calculation
Enter the values and select the action. The calculation rule above explains how the inputs produce the result.
Compare a scenario
Change Units sold on its own, keeping the other inputs fixed. Read both results before changing another assumption.
Worked example
With the example inputs listed above, the result is 234.
Change Units sold from 20 to 22 while keeping every other value fixed. The result becomes 264.4. This comparison isolates that input; it does not forecast how other variables will respond.
Check the stated formula, units and limits before using the result in a decision.
Keep the displayed formula, input units and model scope with the result. Corrections or questions can be sent through the request section on this page.
Content updated: October 11, 2026