Key takeaways
- Start from effective price after discounts.
- Include storage, returns and advertising.
- Use current, marketplace-specific fee data.
- Check the model against real results.
Start with the net selling price
Begin with the price the customer pays, then adjust for promotions and discounts you fund. If you offer coupons or deals, use the effective price during those periods. Note whether any taxes are included, since many markets show prices with sales taxes that are not your revenue.
Subtract Amazon fees
Deduct referral fees, fulfillment or shipping fees and any per-unit service charges. Add an allowance for storage fees, based on how long inventory typically stays and the space it uses. Use current fee schedules for your marketplace and product category.
Subtract product and inbound costs
Include the purchase or production cost, packaging, labeling, inspection, freight to Amazon, duties and any prep costs, spread per unit. Many sellers forget small items that add up, such as labels and inbound handling.
- Cost of goods and packaging
- Inbound freight and duties
- Prep, labeling and inspection
- Insurance and handling
Allow for returns and damage
Estimate the percentage of units returned and the share that cannot be resold, then apply the cost of refunds, return processing and written-off stock. Use your own return history by product rather than a generic assumption.
Include advertising
Allocate advertising spend to products. If you run campaigns, divide spend by units sold, or use total advertising as a percentage of sales. Consider whether the spend creates sales that would not occur otherwise.
Add overhead sensibly
Overheads such as software, salaries and office costs can be allocated per unit or treated separately at the business level. Decide on a consistent approach so comparisons between products are fair.
Build a reusable calculator
Put the steps in a spreadsheet with inputs for price, fees, costs, returns and advertising. Keep a separate tab for each marketplace, because fees differ. Update fee inputs when Amazon announces changes.
A worked example
A seller calculates that a product appears to make a healthy margin before advertising. After allocating advertising and a realistic return rate, the margin shrinks. The calculator shows that raising the price slightly or reducing packaging cost restores a comfortable level, so they test the price change.
Common mistakes
Common mistakes are using revenue instead of profit, forgetting returns, ignoring storage and advertising and relying on outdated fee data. Check your model against actual monthly results and adjust.
Sensitivity: what if costs change?
Once the calculator works, test it. What happens to profit if the supplier price rises, if fees change or if advertising needs to double to hold volume? Run a few scenarios and note the point at which a product stops being worth selling.
Knowing your margin of safety makes decisions about price, sourcing and advertising calmer and faster. It also shows which products are fragile and need attention first.
Your next three steps
Build a calculator you can trust and reuse.
- Create columns for price, each fee, product cost, returns and advertising.
- Test it against one real month of settlement data.
- Run a scenario where costs rise by ten percent and note which products break.
Frequently asked questions
Should overhead be included per unit?
Choose a consistent method. Some sellers include it, others track it at business level.
How often should I update my calculator?
Whenever fees, costs or prices change, and at least quarterly.
This guide is general information. Amazon's fees, policies and program rules change and vary by marketplace, so confirm current details in Seller Central and, for tax or legal questions, with a qualified adviser.