Herminox

What it does

Herminox is six free Amazon calculators for sellers and buyers. Everything runs in your browser — no signup, no email gate, inputs never leave your device. Sellers get FBA profit (2026 fees + fuel), ACoS/TACoS breakeven with max CPC, and inventory recovery: units to get PO cash back after fees. Buyers get unit price, cost per use, and a return tracker with holiday windows and locked capital. Coaches can embed widgets. Independent — not affiliated with Amazon. Confirm fees with Seller Central.

Free Amazon calculators for sellers and buyers — FBA profit, ACoS breakeven, inventory payback, unit price, cost per use, and return tracker. No signup; inputs stay in your browser.

Herminox turns Amazon fine print into clear answers — whether you’re comparing a deal, pricing an offer, or checking margin before you list. Tools designed around the questions people ask before they buy, price, list, or restock on Amazon. Understand what you’re really paying — and whether that “deal” is actually a deal. Know your margin before you list. Model fees, ads, and inventory payback. Herminox is a free, private toolkit for Amazon sellers and buyers. Every calculator runs in your browser — no account, no upload of your numbers. Buyers use Cost Per Use to weigh sticker price against lifetime uses, True Unit Price to compare packs on a fair per-unit basis, and Return & Capital to…from herminox.com

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