How to Calculate True Product Cost for Ecommerce
A step-by-step framework for calculating your all-in product cost including sourcing, shipping, duties, storage, and fulfillment fees.
Quick Answer
True product cost goes beyond supplier invoice. For a $15 product from China, all-in cost before marketing is $19-$24 after freight, duty, platform fees, payment processing, and returns.
Why It Matters
Sellers pricing on supplier cost alone are losing money. Each cost layer chips away at margin. Account for all before setting retail.
Formula / Framework
Example Scenario
$15 supplier, selling $39.99 on Amazon, 8% duty.
| Item | Amount |
|---|---|
| Supplier + Freight + Duty | $18.20 |
| Amazon + FBA + Returns | $12.50 |
| True Cost (before ads) | $30.70 |
| Net before ads | $9.29 (23%) |
Cost Components
| Component | Typical Range | Notes |
|---|---|---|
| Platform Fee | 6.5-15% | Amazon 15%, Etsy 6.5%, eBay ~13%. |
| Payment Processing | 2.9%+$0.30 | Standard processor rate. |
| Returns Reserve | 3-8% | Higher for apparel. |
| Advertising | 10-30% | ACoS target depends on margin. |
Common Mistakes
- Pricing on supplier cost alone
- Forgetting platform fees
- No returns budget
- Ignoring prep/label fees
- Not updating cost model
Seller Checklist
- Map every cost layer
- Build spreadsheet
- Calculate break-even
- Target 40-60% gross margin
- Review quarterly
Ready to calculate your costs?
Try Product Margin Calculator →Official Source Note
Platform fees from marketplace policies. Duty from USITC HTS. Payment rates from Stripe/Shopify.
Frequently Asked Questions
Target margin?
DTC: 60-70% gross before ads, leaving 20-40% net. Amazon: 40-50% gross to account for 15% referral.
Handle cost changes?
Build cost tracker. Re-price proactively. Set margin alerts.
Last reviewed: 2026-07-01