Flea Market Flipper Profit Calculator
Before you buy that thrift store find, calculate your exact net profit on eBay or Facebook Marketplace after fees and shipping.
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eBay ~13.25%, Poshmark ~20%
How It Works & Educational Guide
How To Use
- Enter what you paid for the item (COGS).
- Enter your expected Sale Price.
- Input your shipping costs and the platform fee (usually 13-15% for eBay).
- View your real Net Profit and Margin.
The Thirds Rule Validation
Net Profit = Sale Price - (Item Cost + Shipping + (Sale Price × Platform Fee %))
What the results mean
| Metric | Reselling Reality |
|---|---|
| Gross Sales | The vanity metric. Selling a VCR for $100 looks great until you realize it cost $40 to ship and eBay took $15. |
| Net Profit Margin % | The percentage of the final sale that you keep as pure profit. Aim for >40% otherwise you are just working for the shipping companies. |
Frequently Asked Questions
What is a good profit margin for flipping?
Aim for at least a 3x pricing rule: Sell it for 3x what you paid. This covers fees, shipping tape, and your time while leaving 30-50% net profit.
Do platform fees ruin margins?
Yes. eBay takes around 13-15% of the TOTAL sale (including shipping). You must account for this before pricing.
Sources: eBay Seller Fee Standard Guidelines
Reviewed by Lion Business Team · Updated July 6, 2026