A discount is easy to set and hard to price
Most Amazon promotions carry a fee. Coupons and deals charge an upfront fee plus a share of sales, and the upfront fee is charged even when nothing sells. A Prime Exclusive Discount is free on ordinary days, and in a peak event such as Prime Day it pays an event fee too. Changing the listing price itself is the one option with no fee.
Deal Calculator works this out from your FBA Fee Preview report and your product costs, for every product in one store. It also tells you how many extra sales each option needs just to earn what a normal day earns.
What you get
One interactive page per store, in a single file you open in your browser.
- Profit per unit now and the break-even discount, the largest discount you can give before each sale loses money, with and without advertising.
- A coupon, a Prime Exclusive Discount, a deal and a listing price change side by side: the promotion price, profit per unit after fees, Amazon's fees, and the extra sales each one needs to match the same days at the normal price.
- Controls at the top for the discount, the number of days, whether it falls in a peak event and the extra sales you expect. Change one and every product recalculates.
- A verdict for each option once you enter the extra sales you expect: it pays, it doesn't pay, or it loses money on every sale.
- The rules under each option: deals are by invitation only, upfront fees are charged even if nothing sells, and each marketplace sets minimum discounts, including how far a Prime Exclusive Discount must sit below the lowest price of the last 30 days.
- Fee sources: every fee with a link to Amazon's page and the date it was checked, the points Amazon's pages leave open, and a warning when a source is more than 180 days old.
Six marketplaces, six languages
It covers the US, the UK, Germany, Japan, Canada and Spain. A marketplace outside these six stops the run, because the skill never uses one marketplace's fees for another. The page can be in English, German, Japanese, French (Canada), Spanish or Portuguese, with Amazon's own names for each promotion.
What you need
- Your FBA Fee Preview report from Seller Central (.txt). It gives each product's price, referral fee and FBA fee. Without it, a short list of your products with figures from Amazon's Revenue Calculator works too.
- What each product costs you, landed in your warehouse: one figure per product, or one for all. The skill never estimates it and stops until you give it.
- The country where your business is established, because Amazon's Digital Services Fee depends on it.
- How many units a day each product sells now (recommended). The Business Report for the last 30 days gives you this, or you can type it in. Without it, the page asks for the figure where the verdict would be.
- The Claude desktop app with Claude Cowork. You don't need to install anything else, and the first section of the SOP, Before You Start, shows you how to add the skill.
How a run goes
- Download your Fee Preview report. Section 1 of the SOP shows where to find it.
- Type /amazon-deal-calculator in a Claude Cowork chat and attach the report.
- Give it your product costs, your marketplace, the country where your business is established, the language you want and the promotion you're considering. You can also ask it to compare them all.
- Open the page, set your discount and days, and read the verdicts. The skill creates nothing in Seller Central, so you set up the promotion yourself once the numbers work.
Questions
How do I know the fees are right?
Every fee and rule on the page carries a link to Amazon's page and the date it was checked. When a source is more than 180 days old, the page warns you, and the skill can check each fee against Amazon's page again on request. A changed fee is used only after you confirm it.
Is a promotion that loses money ever worth running?
It can be, as a deliberate investment in ranking with a spending limit. The page shows the profit or loss on each sale, so you can set that limit before you start.
Where it fits
It prices one promotion at a time and works on its own. After the promotion ends, compare the units you really sold with the extra sales the page said you needed.
In the download
One zip file. It holds the skill package, which you add once in Claude Cowork (Customize, then Add, then Upload Skill), and the SOP as both PDF and Word. The SOP is the manual: what to download from Amazon, how to run the skill and how to read the page. Version 2.1.2, updated October 2026.
How to get it
Deal Calculator is a free download. Sign up with your email address and we'll email it to you. Like our paid skills, it comes with its step-by-step guide (SOP).