Operations Calculators
Four operational calculators: compare marketplace fees side by side, estimate sales tax, plan shipping costs, and measure how fast inventory turns.
Inventory Turnover CalculatorTurn COGS and average inventory into turns per year and days of supply.OperationsMarketplace Fee Comparison CalculatorSame product on Etsy, Amazon, eBay and Shopify side by side — fee, net profit and margin each.OperationsSales Tax CalculatorAdd sales tax to any price with example state rates or your own custom rate.OperationsShipping Cost CalculatorEstimate parcel shipping cost by weight, service level and distance zone.Operations
Related areas
Operations FAQs
It depends on the item price and category — which is exactly why the comparison calculator exists. Enter one price and see Etsy, Amazon, eBay, and Shopify side by side with net profit per platform. The cheapest fee isn't always the best choice once audience and conversion are factored in, but it's the right starting point.
It varies wildly by category, but higher generally means cash isn't trapped on shelves: 4–6 turns a year is healthy for many retailers. The calculator converts your COGS and average inventory into turns and days of supply, so slow movers become visible before they become write-offs.
Estimates are planning guides, not professional advice. Read the disclaimer.