How to Calculate True Profit on Every Sale

The True Profit Formula

Profit = Sale Price − (Commission + Processing Fee + Listing Fee + Other Fees) − Shipping − COGS − Packaging

FeePilot handles the fee calculation. You just need to know your COGS and shipping.

Breaking Down Each Cost

• Commission: What the platform takes — 0% to 20% depending on the marketplace.
• Payment processing: Usually 2.9–3.5% + a fixed fee. Some platforms bundle this into their commission.
• Listing fees: Usually $0 except Etsy at $0.20 per listing.
• Shipping: Label cost — either you pay or the buyer pays.
• COGS: What you paid for the item.
• Packaging: Mailers, tissue paper, tape — usually $0.50–$2 per item.

For a deeper dive on fee types, read Marketplace Fees 101.

Example: Selling a $40 Jacket

Bought for $12 at Goodwill. Shipping: $7 (USPS Priority). Mailer: $1.

• eBay (13.6% + $0.40): $5.84 in fees → profit = $14.16
• Mercari (10%): $4.00 in fees → profit = $16.00
• Poshmark (20%): $8.00 in fees → profit = $12.00

Same item, $4 profit swing just from platform choice.

Why COGS Matters

If you got it free (closet cleanout), your COGS is $0 and everything after fees is profit. If you source items to flip, COGS is your biggest variable. Always track it.

A $50 sale with $30 COGS is worse than a $30 sale with $0 COGS.

Don't Forget Packaging Costs

Polymailers ($0.30–0.50 each), boxes ($1–3), tissue paper, thank-you cards, tape. Budget $1–2 per shipment. It adds up at volume — 100 shipments at $1.50 each is $150 off your bottom line.

See Your True Profit Instantly

Enter your sale price, shipping, and item cost. FeePilot shows you the true profit on every platform. Green margin = good, yellow = thin, red = reconsider.

Calculate your true profit →