A return costs much more than the refund
When a sale refunds, the platforms unwind the transaction only part-way. Amazon returns your referral fee minus a 20% refund administration fee, keeps the fulfillment fee outright, charges a returns processing fee (always for apparel and shoes; other categories above a return-rate threshold), and hands you back a product that may no longer be sellable. TikTok's version keeps 20% of the referral fee as an admin charge (capped at $5 per SKU), strands your outbound shipping, and carries the same unsellable-stock risk. Sellers who price without a returns reserve are lending their margin to the returns process — this calculator converts a return rate into the only number that belongs in your pricing: the expected returns cost riding on every unit sold.
At an 8% return rate and a $12.05 all-in return, that is $0.96 on every unit — including the 92% that never come back. Feed that figure into the FBA and TikTok profit calculators as your returns assumption and the two pages agree with each other, and with your settlement.
Worked example
At the defaults — 500 sales a month, 8% returns, a $25 product — Amazon returns cost $0.96 per unit sold ($482 a month) against TikTok's $0.54 ($272). The difference is mostly Amazon's lost fulfillment fee plus returns processing; the shared lesson is that neither platform's returns are free at any plausible rate.
How to use this calculator
- Use your category's real return rate from your last quarter, not a hope — apparel and beauty live in a different world from general merchandise.
- Set the resalable share from what actually goes back on the shelf; opened, worn or hygiene-sealed products are usually a write-off.
- Take the per-unit-sold figure as a pricing reserve: if it is not inside your price, it comes out of your profit.
- Revisit quarterly — a creeping return rate is often a listing problem (sizing, photos, expectations) wearing a finance costume.