Looks like $9.79 profit? Actually loses $0.41.

Product	Price	Profit / unit	Status
Cotton Tee (Etsy)	$24.00	$10.65	HEALTHY
Ceramic Mug (Shopify)	$18.00	$0.87	THIN
Phone Case (Amazon FBA)	$12.99	($0.41)	LOSS

Revenue is up. So why isn't your bank balance?

Most sellers calculate profit as price minus cost. In 2026, a $12.99 sale also pays for:

6.5–15% referral / transaction fees
$0.45 – $7 fixed fee per order — Etsy $0.45, Shopify $0.30, Amazon FBA $3–7 per unit (plus the 3.5% fuel surcharge since April)
$2–4 of ads per order
Shipping you absorb to offer "free shipping"
Packaging — small per unit, big per month
Returns that burn shipping both ways

Result: a phone case that looks like it makes $9.79 actually loses $0.41 on every order. The more it sells, the more it costs you.

What's inside

One .xlsx file, five tabs, nothing to install. Works in Excel 2010+ and Google Sheets.

Fee Table

2026 rates for Etsy, Shopify (Basic / Grow / Advanced) and Amazon FBA across five size tiers, plus FBM. Every row sourced and dated. Editable — your dashboard's numbers win.

Margin Calculator

20 products. Price, COGS, packaging, shipping, ads, return rate in → net profit per unit, net margin and a color-coded HEALTHY / THIN / LOSS status out.

Breakeven Price & Ad Limit

Enter a target margin, get the minimum price. Plus the max you can spend on ads per order and your breakeven ROAS.

6-Month Cashflow

Separates profit on paper from cash in the bank — so you know whether you can afford to restock before it's a problem.

READ ME

A 4-step guide, color legend, and every formula assumption written out. No black boxes.

Two numbers that will save your ad budget

Your ad dashboard shows ROAS. It doesn't show whether that ROAS is profitable. That depends on a number that's different for every product.

MAX AD SPEND PER ORDER

$13.15

Everything left after costs and fees on the $24 tee. Spend more than this per order and the sale loses money.

BREAKEVEN ROAS

1.82×

Your Etsy Ads / Amazon PPC / Meta ROAS on that product must be above this. A "fine-looking" 1.5× is a loss.

Who it's for

Yes, if you…

Sell on Etsy, Shopify or Amazon and are past the hobby stage (roughly $1k+/month)
Run ads and aren't sure they're profitable or just busy
Want to raise prices but are scared, or lower them but don't know the floor
Do dropshipping or print-on-demand and need to know exactly how thin the margin is

No, if you…

Don't have a product yet — there's nothing to calculate
Are looking for "secrets" or "hacks" — this is a calculator, not a course
Refuse to open Excel or Google Sheets

What you get

One .xlsx file — Excel 2010+ and Google Sheets (upload it; formulas, dropdowns and color rules all survive)
3 example products pre-filled — one healthy, one thin, one losing — so you understand it in 60 seconds
Free fee-table updates for 12 months — when a platform changes rates, you get the new file by email
Lifetime access, not a subscription. Single-seller license.

Get Seller Profit OS — $39 Secure checkout by Lemon Squeezy · VAT handled at checkout where applicable

FAQ

How is this different from free templates?

Three ways: (1) 2026 fees are pre-filled with sources, not placeholders; (2) it handles fixed per-order fees, fee caps, optional surcharges and return losses — free templates don't; (3) it gives you breakeven ROAS and cashflow, not just margin.

My dashboard shows different fees.

Expected — fees vary by category, plan, country and programs you've opted into. That's why the table is editable. Change the number, done.

I sell outside the US.

Etsy payment processing and Amazon fulfillment fees vary by country. Edit the Fee Table rows to your marketplace's rates; the logic is identical.

Does it work on my phone?

Via Google Sheets, yes. It's nicer on a laptop.

Is there a refund?

It's a digital file — once downloaded it can't be returned, so no refunds. But if you open it and get stuck, reply to the delivery email and I'll get you unstuck.

Can I share it with my team?

Single-seller license. For teams or agencies, email for a team price.