The ROAS spreadsheet vs RoasFloor: your template was right in January
We are not going to tell you spreadsheets are bad. A well-built sheet with honest inputs computes the same floor we do — the formula is 1 ÷ contribution margin either way, and it is not a secret. The argument is about what happens to that sheet after you close the tab. In the past twelve months, what happened was two rate changes and one change to the legal ground the rates stand on.
The cell that rots
Every ROAS template has a duty cell. It held one number — whatever was true the day it was built. Since then: the Supreme Court struck down the IEEPA tariffs in February 2026 (rates down), Section 301 forced labor duties arrived in July (12.5% China and Vietnam, 10% India — rates up), and in between, CBP moved the $800 de minimis suspension out of executive-order territory into standing regulation — not a new rate, but the end of any reasonable plan for the old 0% coming back. The full sequence is in the de minimis guide, and what it did to ten categories’ floors is computed, not estimated. A duty cell copied forward from early 2025 has been wrong twice over on the number and once on the ground it stood on — and a wrong duty cell does not look wrong. It looks like a number.
The subtler failure: duty is not one number. It is layers — MFN by category, Section 301 China lists by 10-digit HTS code, forced labor duty by origin, each with its own legal basis and its own way of changing. A single cell flattens that into something that cannot be updated correctly even by someone who reads the Federal Register, because the cell has forgotten which layers it was made of.
What maintaining the sheet actually means
If you keep the spreadsheet, this is the honest job description. Each row links the calculator that does that row for free:
- Track duty by origin and category, layer by layer, and re-enter it on every change — the import tariff calculator shows the current stack with sources and dates.
- Recompute landed cost when freight or packaging moves — the landed cost calculator, duty on customs value, not on price.
- Keep the floor formula honest about fees and returns — the break-even calculator, and the step-by-step guide if you want to verify our arithmetic against yours.
- Re-run every SKU after each change, and notice which ones crossed their line — in the workspace that is the portfolio view and a tariff alert; in the sheet it is you, remembering.
Where the spreadsheet genuinely wins
Symmetry, because you will notice if we skip it: a sheet is infinitely flexible, free, works offline, and everyone on the team already knows how to use it. If your costs are stable, your goods are domestic, and duty is not in your unit economics, a good template and discipline are enough — and the guide gives you the formula to build one. Tariff-exposed importers are the people the sheet quietly betrays.
The actual comparison
Not spreadsheet vs software — a static number vs a maintained one. The calculators are free and carry the maintained tariff table; the paid workspace exists for the part no sheet does at all: noticing, without being asked, that a rate moved and your floor moved with it. That is $19 a month — a fraction of what paid ROAS templates charge once for numbers that started aging the day they shipped.
Sources
Every tariff layer and its primary source is documented on the methodology page. Rates last updated: 2026-08-22.