Verimargin overlays accurate FBA fees, margin, and ROI on every Amazon product page. A focused Chrome extension for sellers who care more about correct numbers than another bloated dashboard.
price − fees − COGS = the truth
Three steps. The free extension needs no setup, no account, no card.
Add Verimargin from the Chrome Web Store. No sign-up — the core calculator is free, forever.
The overlay reads the page — price, dimensions, weight, category — entirely inside your browser.
Accurate FBA fees, margin, and ROI on the spot. Enter your cost once — it's remembered per product.
Every fee, computed the way Amazon actually charges it — then shown as a receipt you can audit line by line.
Referral fees with Amazon's marginal "portion of price" brackets, FBA fulfillment by size tier, and monthly storage — 2026 US rates (effective January 15, 2026; re-verified each release) against Amazon's published schedule.
When a number is an estimate — missing dimensions, unmatched category — it prints in pencil, with a ~. No competitor admits what it doesn't know. We typeset it.
The free extension is 100% on-device. Your costs are saved per product in your own browser — never sent to a server, never tracked. A future Pro tier may add opt-in cloud sync; it'll be off by default. Privacy policy.
The incumbents charge $29–229/month and answer questions you didn't ask. Verimargin answers one.
Just the math, on the page where you buy.
Full fee math, profit, margin, ROI, and saved costs. No card, no account.
A paid tier comes when there's something genuinely worth paying for. Not before.
Free, on every Amazon product page. No account, no card.
Add to Chrome — FreeYes — the core calculator is free, forever. No account, no card. A Pro tier may come later; the free tier stays.
Standard, variation, bundle, out-of-stock, and Subscribe & Save product pages on amazon.com.
Fee math is verified against Amazon's own FBA Revenue Calculator and the 2026 US rate card — including the marginal "portion of price" referral brackets most calculators get wrong, and the 3.5% fuel & logistics surcharge as its own line. When a number is an estimate, it's shown in pencil rather than asserted.
No. The free Verimargin extension is 100% on-device — your costs (COGS) are stored only in your browser and never leave it. It has no servers, no account, and no tracking. (A future Pro tier may add opt-in cloud sync, off by default — the free tier always stays on-device.)
Not yet — v1 supports amazon.com (US). Other marketplaces are on the roadmap.
It's focused and honest: accurate fee math on the product page, free, with no bloated dashboard and no invented confidence. When it doesn't know a number, it says so instead of guessing.