https://marketplacemath.comFree marketplace fee, seller profit, margin, and markup calculators with current formulas and transparent sources.en-ushttps://marketplacemath.com/guides/amazon-fba-and-seller-feeshttps://marketplacemath.com/guides/amazon-fba-and-seller-feesCalculate 2026 Amazon U.S. FBA fulfillment, referral, storage, inbound, and selling-plan fees with formulas and worked profit examples.https://marketplacemath.com/guides/how-much-does-ebay-takehttps://marketplacemath.com/guides/how-much-does-ebay-takeUnderstand current eBay final value fees, order fees, promoted listings, category tiers, and the difference between payout and profit.https://marketplacemath.com/guides/paypal-business-feeshttps://marketplacemath.com/guides/paypal-business-feesCompare current U.S. PayPal Checkout, card, and QR transaction fees and learn how to calculate net payment and profit.https://marketplacemath.com/guides/stripe-payment-processing-feeshttps://marketplacemath.com/guides/stripe-payment-processing-feesLearn current U.S. Stripe processing fees for online cards, Terminal, ACH, Link, international cards, and reverse pricing with worked examples.https://marketplacemath.com/guides/how-much-does-etsy-takehttps://marketplacemath.com/guides/how-much-does-etsy-takeSee how Etsy listing, transaction, payment processing, and Offsite Ads fees stack together for a U.S. seller.https://marketplacemath.com/guides/whatnot-seller-feeshttps://marketplacemath.com/guides/whatnot-seller-feesUnderstand current Whatnot U.S. commission and payment-processing fees, their different bases, and how to estimate profit.https://marketplacemath.com/guides/depop-seller-feeshttps://marketplacemath.com/guides/depop-seller-feesCalculate current U.S. Depop payment processing and boosted-listing fees after the removal of the standard selling fee.https://marketplacemath.com/guides/grailed-seller-feeshttps://marketplacemath.com/guides/grailed-seller-feesUnderstand Grailed's current under-$120 and $120-plus commission tiers, processing rates, shipping basis, and seller profit.https://marketplacemath.com/guides/mercari-selling-feeshttps://marketplacemath.com/guides/mercari-selling-feesUnderstand Mercari's current U.S. 10% selling fee, what is included in the basis, and how to move from payout to profit.https://marketplacemath.com/guides/how-much-does-poshmark-takehttps://marketplacemath.com/guides/how-much-does-poshmark-takeCalculate Poshmark's two U.S. seller-fee tiers and understand how offers, shipping discounts, and item cost affect profit.https://marketplacemath.com/guides/how-to-calculate-break-even-pointhttps://marketplacemath.com/guides/how-to-calculate-break-even-pointCalculate break-even units and revenue with fixed costs, variable costs, contribution margin, marketplace fees, and worked examples.https://marketplacemath.com/guides/how-to-calculate-profit-marginhttps://marketplacemath.com/guides/how-to-calculate-profit-marginLearn the formulas for gross profit, gross margin, net profit, net margin, and revenue required to reach a target margin.https://marketplacemath.com/guides/markup-vs-marginhttps://marketplacemath.com/guides/markup-vs-marginUnderstand the difference between markup and margin, convert between them, and set prices that cover direct and marketplace costs.https://marketplacemath.com/guides/square-payment-processing-feeshttps://marketplacemath.com/guides/square-payment-processing-feesLearn current U.S. Square processing fees for in-person, online, invoice, keyed, API, and Afterpay payments with formulas and worked examples.https://marketplacemath.com/guides/venmo-business-and-transfer-feeshttps://marketplacemath.com/guides/venmo-business-and-transfer-feesLearn current Venmo business, goods and services, Tap to Pay, and Instant Transfer fees with formulas, examples, and payout guidance.