MerchantCalcs publishing

Seller blog

Sourced, practical articles for making e-commerce decisions with better numbers.

Current publications

Research and guides

Each article shows its formulas, changing assumptions and verification sources.

Etsy seller profitEtsy Fees, Profit and Pricing: A Practical Seller GuideBuild an Etsy price from real order economics instead of subtracting one headline fee from revenue. Customs and logisticsHS Codes, Import Duty and Landed Cost for E-commerceUnderstand what an HS code can and cannot tell you before estimating customs duty, import tax and product landed cost. PricingMargin vs. Markup: The Pricing Difference Sellers Must KnowA practical explanation of why a 50% markup is not a 50% margin, with examples for small sellers. E-commerceHow to Calculate True Profit per OrderA step-by-step order profit method that includes product cost, shipping, ad spend, platform fees and returns. FinanceUnderstanding Contribution Margin for Small BusinessesUse contribution margin to decide which products, bundles or campaigns deserve more attention. AdvertisingHow Break-Even ROAS WorksLearn why a high ROAS can still lose money when margins are thin. E-commerceHow Returns Affect E-commerce ProfitModel refunds, reverse shipping and resale loss before a product looks healthier than it is. InventoryReorder Point and Safety Stock ExplainedAvoid stockouts by combining demand, supplier lead time and a realistic buffer. LogisticsDimensional Weight Explained for Online SellersWhy large lightweight packages can be billed above their scale weight. LogisticsUnderstanding Landed Cost Before You ImportBring freight, duties, insurance and handling into one per-unit cost. PricingHow Discounts Affect ProfitCalculate how many extra units a discount must sell before it is worth running. PricingCommon Product Pricing MistakesThe quiet pricing errors that turn popular products into weak businesses.