US ecommerce · USD · five focused tools
Know the margin before the sale.
Turn product costs, platform fees, returns, and ad spend into a clear profit decision. No account, no spreadsheet, no hidden benchmark.
Tool ledger
Five decisions. One consistent cost model.
Start with the broad profit model, then use a specialist tool when pricing or advertising is the question.
Ecommerce profit
Full order economics with returns, fees, ads, and allocated monthly costs.
Use calculator 02 / CoreProduct pricing
Back into a price from costs and target margin.
Use calculator 03 / AdsBreak-even ROAS
Find the ad efficiency line your economics can support.
Use calculator 04 / Amazon AdsAmazon ACoS
Compare current ad ratios with product-level target thresholds.
Use calculator 05 / Etsy USEtsy fee + profit
Versioned US fee estimate with profit and target-price output.
Use calculatorOperating rule
Inputs first. Assumptions visible.
MarginTally does not invent a "good" margin or silently fill platform costs. Every result is tied to the values you enter, and every platform-specific rate is versioned against an official source.
- Money is calculated at fixed precision, then displayed to the nearest cent.
- Pricing rounds upward so ordinary rounding never drops you below your target margin.
- Advertising math starts from revenue minus non-ad costs, not industry guesses.
Profit model
Net profit = revenue − product costs − fulfillment − payment fees − platform fees − expected return loss − ads − other costs − allocated fixed costs
Net margin = net profit ÷ revenue. When revenue is zero, margin is shown as unavailable.