Methodology

CrossMargin Methodology

CrossMargin calculators are designed for operating estimates. The goal is to bring scattered cost items into one working model. Final decisions should still be checked against platform invoices, freight quotes, tax rules, and your own order data.

Profit calculation

The profit calculator uses this simplified model: net profit per unit = selling price - product cost - freight or fulfillment cost - platform fee - advertising cost - return loss - other cost. Margin = net profit per unit / selling price.

Break-even ACOS

Break-even ACOS estimates the highest advertising cost of sales a product can tolerate before ad orders become unprofitable. The simplified model is break-even ACOS = pre-ad profit / selling price. Advertising cost should not be deducted twice when calculating this number.

Landed cost

The landed cost calculator allocates sourcing cost, freight, duty, VAT or GST, warehouse handling, labeling, and other pre-sale costs to each unit. Shipment-level costs are allocated by quantity. Dimensional weight is shown as a planning signal, while real billing depends on the carrier or freight forwarder.

Returns, discounts, and free shipping

Return loss is estimated as a percentage of selling price. Discounts should be handled through the real transaction price rather than the list price. Free shipping should be included in freight or fulfillment cost because it is still paid by the seller.

Fee sources and review boundary

CrossMargin does not maintain a universal fee table. Marketplace fees, fulfillment charges, taxes, carrier rates, and promotional rules change by market, category, product dimensions, and account. Enter the current values from your own invoices or platform reports before using a result for a purchase order, price change, or ad budget.

For Amazon models, verify selling and FBA costs with Amazon's fee and cost estimator and FBA overview. These sources describe Amazon's current fee-estimation workflow; they do not replace account-specific charges, freight quotes, or tax advice.

Methodology reviewed: July 13, 2026. Formula changes, broken source links, and materially changed platform references are treated as maintenance issues and should be reported through the contact page.

Ads and result independence

CrossMargin may display ads or affiliate links in the future, but ads do not participate in the calculator logic and do not change formula results. Tool inputs are still processed in the browser, and the calculation model is based on the formulas described here.