Reverse Margin (Target COGS) Calculator for Amazon sellers — work backwards from your selling price to a safe supplier cost before you reach out. This free tool turns a selling price into a target landed COGS (product plus freight and duty to FBA), factoring in Amazon fees, FBA fulfilment, ads, and other per-unit costs — so you can quote suppliers with confidence and still hit your margin. Everything runs in your browser; nothing is stored or sent anywhere.
How to use this calculator
- Enter your selling price and any discount you run, so the tool works from your true net price.
- Add Amazon fees — the category referral %, and your FBA fee per unit.
- Add per-unit costs — inbound freight to FBA, plus ads % and other % of net for promos, returns allowance, and the like.
- Set your desired margin %, then pick an anchor strength for how aggressive your opening offer should be.
- Read the outputs — Max Target COGS, profit per unit, and an opening offer. Optionally enter a real supplier quote to sanity-check the resulting margin.
Let P = your price, d = discount %, Net = P × (1 − d). Percentage costs apply on Net.
- Referral:
ref% × Net. Ads: ads% × Net. Other: other% × Net.
- Desired profit:
margin% × Net.
- Max Target COGS:
Net − referral − FBA − inbound − ads − other − desired profit.
- Opening offer:
Target COGS × (1 − anchor%) — a first quote below your ceiling.
- Break-even Ad %: the ad spend % of net at which profit hits zero, given a quoted COGS.
Inputs & outputs at a glance
Inputs
- Amazon average price & your price
- Discount %, referral %
- FBA fee, inbound/freight (₹ per unit)
- Ads % and other % of net
- Desired margin %, anchor strength, optional quoted COGS
Outputs
- Max Target COGS — the most you can pay per unit
- Profit per unit at target COGS
- Opening offer for your first supplier message
- Status (green / amber / red) on your margin health
- With a quote: liquidation price, break-even ad %, min price
Worked example
Your price ₹1,499 · 0% discount · referral 15% · FBA ₹85 · inbound ₹40 · ads 8% · other 2% · desired margin 20%
Net = ₹1,499. Referral ₹224.85, ads ₹119.92, other ₹29.98, desired profit ₹299.80.
→ Max Target COGS ≈ ₹699, profit/unit ≈ ₹300, opening offer (15% anchor) ≈ ₹595.
Tips & edge cases
- Fees change by category and size tier — always pull the latest Fee Preview / FBA rate card.
- Treat promos and coupons as costs — add them to Other %, or reduce your price.
- Add a small returns allowance to Other % for a truer margin.
- Convert supplier quotes to your selling-marketplace currency before comparing to Target COGS.
- Be consistent with duty — put it inside COGS or inside Other, but not both.
Glossary
- Target COGS (landed): product + freight/duty/packaging to get a unit sell-ready at FBA.
- Referral fee: Amazon's category-based percentage fee on the sale.
- FBA fee: per-unit fulfilment fee based on size/weight tier.
- Net margin: profit after all variable costs ÷ net price.
- Break-even Ad %: the ad spend % of revenue that yields zero profit.
FAQs
What is Target COGS?
It's the maximum landed cost you can pay per unit — product plus freight and duty to FBA — and still hit your desired margin after all Amazon fees. Quote at or below it and your margin is protected.
Why apply percentage costs on net price, not the listed price?
Because after a discount, your true revenue is the net price. Referral fees, ads, and other percentage costs should be measured against what you actually receive, not the pre-discount price.
What does the opening offer do?
It's a suggested first quote to send a supplier, set below your Max Target COGS by your chosen anchor strength — so you have room to negotiate up while staying inside your margin.
How do I account for PPC?
Enter your planned ad spend as a percentage of net price in the Ads % field, or fold it into Other %.
Where do I find the FBA fee?
Use Fee Preview in Manage Inventory, or the official FBA rate card for your product's size and weight tier.
Is my data saved anywhere?
No. Everything is calculated in your browser — nothing you type is uploaded or stored on any server.
