Online Arbitrage Profit Calculator: What to Include Before You Buy
A practical guide to calculating landed cost, marketplace fees, shipping, tax, returns and expected margin before buying an online arbitrage product.
Why source price alone is not enough
A low purchase price can look attractive, but it does not tell you whether a product will remain profitable after every cost is included. A useful online arbitrage calculation starts with the source price and then adds the costs that occur between buying the item and completing the customer order.
For cross-border selling, those costs can include packing, courier charges, currency conversion, marketplace fees, tax assumptions and expected return losses. Ignoring even one recurring cost can turn an apparently profitable item into a loss-making listing.
The core calculation
Start with your expected selling price. Subtract product cost, shipping, marketplace fees, payment or currency costs, packing, taxes that apply to your workflow and a realistic allowance for returns or refunds. The remaining amount is the expected profit, not a guaranteed profit.
Margin should be calculated against the selling price so you can compare products consistently. Keep the assumptions visible and editable; if shipping or marketplace fees change, recalculate before buying more inventory.
Use dimensions and weight, not just item weight
International couriers may charge by volumetric weight when a parcel occupies more space than its actual weight suggests. Record package length, width and height as well as actual weight, then use the chargeable weight required by your courier.
This is especially important for low-value bulky products, where shipping can consume a large share of the selling price.
Add a return-loss assumption
Returns are part of e-commerce. A product with a high return rate can have a very different real margin from the margin shown on a single successful sale. Use your own historical return rate when available and model the expected loss from refunds, non-recoverable shipping and damaged inventory.
Aranavi OA is designed to keep these assumptions visible so a seller can review the numbers before making a purchase decision.