Platform Fee Calculator: Net Profit Across eBay, Facebook Marketplace, Mercari & 6 More (2026)

How the Calculator Works

The live calculator above runs entirely in your browser — no signup, no API calls, no data leaves the page. Enter three numbers (sale price, item cost / COGS, shipping you absorb), pick a platform from the dropdown, and the net profit, effective fee %, and line-by-line fee breakdown recalculate on every keystroke.

• Sale price — the final price the buyer pays (gross).
• Item cost / COGS — what you paid to acquire the item, plus any refurb supplies.
• Shipping you absorb — the label cost you eat (zero for local or buyer-pays-shipping listings).
• Platform — selects the current 2026 fee schedule from the constants table below.
• Payment processing override — optional. Useful when a platform changes a rate mid-cycle or when you're modeling a promoted-listing surcharge.

The "Copy shareable link" button encodes the inputs into a URL query string so you can send a fully populated scenario to a partner, a subreddit, or your own notes. The "Compare all 9 platforms" button ranks every supported marketplace by net profit at the current inputs — useful for cross-list pricing decisions.

Current Fee Rates on the 9 Most-Used Resale Platforms

The table below is the exact fee schedule the calculator applies. Every rate links to the platform's official fee documentation, dated 2026-04-17. No affiliate math, no "estimates."

What Fees Most Flippers Forget to Subtract

The headline rate on a fee page is never the whole story. Four costs routinely erase 3-8 percentage points of margin if you don't model them up front:

• Shipping absorbed on "free shipping" listings. eBay, Mercari, and Poshmark all charge selling fees on the buyer-facing total for free-shipping listings, so the label you pay is taxed twice — once as an outbound cost and once as fee-inflating gross.
• Return allowance. Plan on a 5-8% return reserve on electronics and apparel; 2-3% on tools and housewares. eBay returns the final-value fee when you refund, but you eat the inbound label and restocking time.
• Refunded order fees. Some platforms keep a portion of the per-order flat fee or the processing fee on partial refunds — read the refund policy alongside the fee page for each marketplace you use.
• Promoted Listing ad rates. eBay Promoted Listings Standard ads typically run 2-15% on top of the base fee, charged only on attributed sales per eBay's Promoted Listings documentation. Mercari Promote and Poshmark Promoted Closet work the same way. These stack — a 13.6% eBay fee becomes ≈20% effective when you enroll.

Choosing the Right Platform by Price Point

Fee structures have sweet spots. Use these rules to decide which marketplace to list on first, then cross-list only if the item hasn't sold in 7-14 days.

• Under $15: Poshmark's 20% is punishing but the $2.95 flat floor makes sub-$15 sales viable. Below $10, Mercari (10% + 2.9% + $0.50) nets more. Below $5, don't ship — use Craigslist or Facebook Marketplace Local.
• $15–$50: Facebook Marketplace Shipped (10% flat) and Mercari tie on most items. eBay is rarely worth it under $50 because the $0.30 per-order fee compresses margin.
• $50–$250: eBay is usually the velocity winner. You absorb 13.6% but buyer reach is 5-10x Mercari. Poshmark stays competitive for apparel only.
• $250–$1,000: eBay and Facebook Marketplace Shipped both work. eBay if the item is searchable (model numbers, brand); FBM if the item is visual/photogenic (furniture, bikes, decor).
• $1,000+: Local handoff on Facebook Marketplace or Craigslist for zero-fee sales. eBay managed payments hold funds 3-21 days on high-value first sales, which is a real cash-flow cost.
• Handmade or vintage (20+ years): Etsy. The 6.5% transaction fee + $0.20 listing is the cheapest route to a buyer base that actually pays for craft markup.

Worked Example: A $180 Power Drill Flip Across All 9 Platforms

Setup: You bought a used DeWalt 20V drill kit for $60 at a Saturday estate sale, spent $12 on a USPS Ground Advantage label, and listed it for $180. Here's what you actually take home on each platform, using the calculator's 2026 rates:

Takeaways: $36 of margin swings between Poshmark (worst) and the two local options (best) on the same transaction. If the drill is within a 20-mile radius of a motivated buyer, Facebook Marketplace Local is the obvious choice. If you need scale and ship-to-anywhere, Facebook Marketplace Shipped at 10% beats eBay by ≈$7 net — unless eBay's reach shortens your sell-through by a week, in which case eBay wins on velocity-adjusted margin.

How Often These Fee Rates Change (and How to Stay Current)

Major marketplaces update fee schedules 1-3 times per year. Rate hikes are typically announced 30-60 days in advance on the seller help page before the rollout date. Recent cadence:

• eBay: final-value fee structure restructured in 2023 (removed the PayPal-era separate 2.9% processing) and trimmed insertion-fee caps in 2024. See eBay's selling fees page for the current consumer-category rate.
• Facebook Marketplace: Meta waived all selling fees from 2022 through early 2024, then reintroduced the 10% shipped-item fee. Local has remained fee-free the entire time. Tracked at facebook.com/business/help/427957319496589.
• Mercari: raised the selling fee from 10% to 10% + 2.9% + $0.50 processing in late 2023. Current policy at help.mercari.com.
• Poshmark: the $2.95 / 20% structure has held since 2019; updates on poshmark.com/how_it_works.
• Depop: restructured to 10% + 3.3% + $0.45 in 2022 per help.depop.com.
• Etsy: last major change was the 2022 transaction-fee bump from 5% to 6.5% per help.etsy.com.

Bookmark this page — the calculator above pulls from a single constants table that we refresh quarterly against the official sources listed below. If you spot a rate that's drifted, the "Override payment processing" field lets you correct it mid-calculation.