What costs does an Amazon FBA profit calculator need to include?

An Amazon FBA profit calculator needs ad spend per product, returns, promotional discounts and storage fees on top of the usual COGS, selling price, FBA fees and referral fees. Ad spend per product means what was spent advertising that specific product rather than total ad spend. Returns matter because Amazon takes back the referral fee credit and charges a return processing fee. Promotional discounts include coupons, Lightning Deals and Subscribe & Save. Storage fees vary by season and product size.

Why isn't a profit spreadsheet enough for Amazon sellers?

A profit spreadsheet is a snapshot from whenever it was last updated, and Amazon's costs do not hold still. FBA fees change, COGS change when suppliers or shipping costs shift, ad spend fluctuates daily, and returns happen unpredictably. A spreadsheet that was accurate on January 1st is wrong by January 15th. Sellers who update monthly end up making daily decisions on data that is two to four weeks old.

How much of Amazon revenue do returns take?

On some products returns consume 5-15% of revenue. That is not only the refunded sale: Amazon takes back the referral fee credit and charges a return processing fee, so a returned unit costs more than it earned. Returns are one of the four cost categories most often absent from a seller's profit spreadsheet, alongside per-product ad spend, promotional discounts and storage fees.

Amazon FBA Profit Calculator: Why Spreadsheets Aren't Enough

Your spreadsheet is missing costs, lagging behind reality, and can't account for ad spend per product. Here's what real profit tracking looks like.

The short version

A profit spreadsheet is usually incomplete rather than wrong: it accounts for COGS, price, FBA fees and referral fees, and omits the costs that decide the answer.
The four costs most often missing are ad spend for that specific product, returns, promotional discounts such as coupons and Subscribe & Save, and storage fees.
Returns can consume 5-15% of revenue on some products, because Amazon takes back the referral fee credit and charges a return processing fee.
A spreadsheet is a snapshot, so sellers who update monthly are making daily decisions — what to advertise, how much to bid, when to reorder — on data that is two to four weeks old.

Every Amazon seller has a spreadsheet. It has columns for COGS, selling price, maybe FBA fees, and a formula at the bottom that says "profit." The problem isn't that the spreadsheet is wrong — it's that it's always incomplete and always out of date.

What your spreadsheet is missing

A typical seller's profit spreadsheet accounts for COGS and selling price. A good one adds FBA fees and referral fees. But almost none of them include:

Ad spend per product — not total ad spend, but how much you spent on ads for THIS specific product. Most sellers can't answer this question without digging through campaign reports.
Returns per product — Amazon takes back the referral fee credit and charges a return processing fee. On some products, returns eat 5-15% of revenue.
Promotional discounts — coupons, Lightning Deals, and Subscribe & Save discounts all reduce revenue per unit but don't show up in a static spreadsheet.
Storage fees — monthly and long-term storage fees that vary by season and by product size.

Miss any one of these and your "profit" number is fiction. Miss two or three and you could be losing money on products you think are profitable.

The real problem: spreadsheets don't update themselves

Even if your spreadsheet has every cost category, it's a snapshot from whenever you last updated it. FBA fees change. Your COGS change when you negotiate with suppliers or when shipping costs shift. Ad spend fluctuates daily. Returns happen unpredictably. A spreadsheet that was accurate on January 1st is wrong by January 15th.

The sellers who rely on spreadsheets typically update them monthly — meaning they're making daily decisions (which products to advertise, how much to bid, when to reorder) based on data that's 2-4 weeks old. In a marketplace as dynamic as Amazon, that lag is expensive.

What real profit tracking looks like

Real profit tracking pulls data from Amazon automatically — sales, fees, ad spend, returns — combines it with the COGS you enter once, and shows you actual profit per product, per day, updated as the data flows in. You don't maintain it. You read it.

The difference between a spreadsheet and a live profit dashboard is the same as the difference between a paper map and GPS. Both show you where you are. Only one updates when the road changes.

RedHen Labs syncs your Amazon data daily — orders, FBA fees, referral fees, ad spend per product, returns — and combines it with your COGS to show real profit per product. Enter your costs once. See your margins every day. Try it free for 14 days.

Frequently asked questions

What costs does an Amazon FBA profit calculator need to include?: An Amazon FBA profit calculator needs ad spend per product, returns, promotional discounts and storage fees on top of the usual COGS, selling price, FBA fees and referral fees. Ad spend per product means what was spent advertising that specific product rather than total ad spend. Returns matter because Amazon takes back the referral fee credit and charges a return processing fee. Promotional discounts include coupons, Lightning Deals and Subscribe & Save. Storage fees vary by season and product size.
Why isn't a profit spreadsheet enough for Amazon sellers?: A profit spreadsheet is a snapshot from whenever it was last updated, and Amazon's costs do not hold still. FBA fees change, COGS change when suppliers or shipping costs shift, ad spend fluctuates daily, and returns happen unpredictably. A spreadsheet that was accurate on January 1st is wrong by January 15th. Sellers who update monthly end up making daily decisions on data that is two to four weeks old.
How much of Amazon revenue do returns take?: On some products returns consume 5-15% of revenue. That is not only the refunded sale: Amazon takes back the referral fee credit and charges a return processing fee, so a returned unit costs more than it earned. Returns are one of the four cost categories most often absent from a seller's profit spreadsheet, alongside per-product ad spend, promotional discounts and storage fees.

RedHen Labs — Amazon profit tracking & PPC automation, flat-rate.