Start with collected sales
In a COD workflow, dispatched sales and collected sales are not interchangeable. Start a contribution calculation with delivered orders and the amount received, then account for refunds or other adjustments where relevant.
Bring the costs into the same view
Include the cost of sold goods, shipping, packaging, return fees and acquisition spend. Payment fees, discounts, taxes and damaged or unrecoverable returned inventory may require additional lines.
Use contribution carefully
Contribution is revenue less the variable costs included in the calculation. It is not net profit. Salaries, software, rent and other overhead still matter when assessing the whole business.
Change one assumption
Explore what happens when delivery rate, ad spend or shipping cost changes while the other inputs stay fixed. This makes the sensitivity of the model visible without treating a scenario as a forecast.
The calculator on this site is a simplified scenario tool. It assumes returned stock is recoverable and excludes overhead, taxes and payment fees.