Our Methodology

Where the Fee Rates Come From

Every default rate used in our calculators is taken from each marketplace's own published seller or supplier fee documentation — the same page an official seller account would point you to. We don't estimate rates from third-party blogs, forums, or outdated screenshots. Each calculator links directly to the exact official source page we used, right next to the tool itself, so you can verify the current number in a few seconds without searching for it yourself.

Where a marketplace publishes more than one rate for a category, account type, or country, we use the most common, standard rate — the one that applies to the majority of sellers in the majority of categories. This is clearly the right starting point for most people, but it's an average, not a guarantee: your specific category or seller plan can carry a different official rate.

For Amazon, eBay, Walmart, and Shopify, we go a step further: every calculator and category page for these marketplaces shows a full, official category-by-category (or plan-by-plan, for Shopify) rate table beneath the "closer look at each fee" section — not just the single default used in the calculator. For Etsy, we checked directly and confirmed its core fees genuinely don't vary by category, so we say that plainly instead of inventing a table. For Flipkart, no single official public rate table exists outside a seller's own dashboard — rather than publish an unverifiable third-party estimate as fact, we say so and point sellers to their own Seller Hub.

What "Last Verified" Means

Every calculator page shows a "Rates last verified" date next to its source link. That date is when we last checked the live default rate shown on that calculator against the marketplace's own current fee page. Marketplace fees do change over time — sometimes announced well in advance, sometimes updated quietly — so this date is there to give you an honest sense of how fresh the number is, rather than implying every rate is checked in real time.

Our current full-dataset check across all 35 marketplaces was completed on 2026-09-01. We recheck the full set on a regular cycle, and any platform we verify outside that cycle shows its own, more recent date.

How the Calculations Work

Once we have a marketplace's fee structure, the math itself is simple and transparent — there's no hidden adjustment or rounding beyond standard currency rounding. Depending on the fee, we apply one of a small number of calculation types:

• Percentage of price — a straight percentage of your selling price.
• Percentage with a minimum — a percentage of price, with a fixed floor amount that applies on cheap items.
• Percentage with a cap — a percentage of price, up to a fixed ceiling on expensive items.
• Flat fee — a fixed amount charged the same way on every order.
• Percentage plus flat — a percentage of price plus a small fixed add-on.
• Per unit — a fixed amount multiplied by quantity.
• Weight-tiered — a fee that depends on which weight band your item falls into.
• Percentage of shipping — a percentage applied to your shipping cost rather than your selling price.

Profit calculators subtract every applicable fee, your product cost, and your shipping cost from your selling price. Margin is that profit shown as a percentage of the selling price. All of this runs directly in your browser using JavaScript — nothing you type is sent to our servers or stored anywhere.

What Every Calculator Excludes

To keep each tool fast, simple, and honest, every calculator on this site deliberately leaves out costs that depend on choices made after a product is listed rather than on the sale itself. None of these are hidden — they're simply outside what a single-sale calculator can reasonably estimate:

• Advertising or sponsored-listing spend
• Promotional discounts, coupons, or deal-event pricing
• Long-term storage or warehousing charges for slow-moving inventory
• Return, refund, or chargeback processing costs
• Optional subscription or paid-plan fees charged separately from per-sale fees
• Taxes, duties, or currency-conversion charges on cross-border sales

Treat every result as the core, per-sale number to build your pricing from — a strong, accurate starting point, not the final word on every cost in your business.

Platforms Without a Public Seller Program

A small number of retailers on this site — JB Hi-Fi, Kmart Australia, IKEA, Costco Canada, Chemist Warehouse — don't publish a standard, per-sale seller marketplace commission the way Amazon, Flipkart, or eBay do. These retailers typically work with suppliers through private wholesale or vendor agreements rather than an open seller marketplace.

For these platforms, the rate shown is a clearly labeled, illustrative estimate based on typical retail margins in similar categories — not an official published rate. Each of these calculators carries a visible notice saying exactly this, and we'd always recommend contacting that retailer's supplier or partnership team directly for a real quote rather than relying on our estimate for an actual business decision.

Corrections

If you're a seller on any of these marketplaces and notice a rate that looks out of date or incorrect, we want to know — a quick note through our contact page with the correct, sourced rate helps us fix it faster than our own recheck cycle would catch it. We'd rather be corrected quickly than be wrong for months.