Turn fees, shipping, savings, and profit into clear numbers.
RotoCurve is a practical calculator hub for resale math, marketplace fees, shipping decisions, purchase savings, and small business planning. No fluff. Just the numbers you need before you click buy, list, ship, or renew.
Popular tools
Estimate net profit after eBay fees, payment fees, shipping, taxes, and item cost.
MarketplaceAmazon Seller Fee CalculatorEstimate Amazon seller net profit using referral fees, fulfillment costs, inbound cost, and product cost.
MarketplaceMercari Profit CalculatorEstimate profit on a Mercari sale after fees, shipping, supplies, and item cost.
MarketplacePoshmark Fee CalculatorCalculate estimated Poshmark seller profit with flat or percentage fees.
MarketplaceEtsy Fee CalculatorEstimate Etsy net profit after transaction fees, payment fees, listing fees, ads, shipping, and item cost.
Profit MathBreak-Even Price CalculatorFind the minimum sale price needed to cover costs, percentage fees, and fixed fees.
ShippingDimensional Weight CalculatorCalculate billable dimensional weight from package length, width, height, divisor, and actual weight.
ShippingShipping Markup CalculatorWork out shipping markup, margin, or loss when charging a buyer for shipping.
SavingsDiscount and Cashback CalculatorCombine sale discounts, coupons, cashback, and tax to find the real net price.
SavingsSales Tax CalculatorCalculate sales tax, pretax price, and total purchase price quickly.
Profit MathProfit Margin CalculatorConvert revenue and cost into gross profit, profit margin, and markup.
Profit MathMarkup CalculatorCalculate sale price from cost and target markup, or see the margin created by a markup.