NFT Marketplace Fee Calculator

WHAT IT DOES

NFT Marketplace Fee Calculator watches the current page for NFT listing prices and sale transactions, detects the marketplace platform from URL or page content, applies known fee structures (marketplace fees, creator royalties, gas costs), and calculates total cost for buyers and net proceeds for sellers, displaying a breakdown with alerts when fees significantly impact profitability. The tool helps you understand the true cost of NFT transactions before buying or selling.

WHERE IT RUNS

This tool works on any webpage that displays NFT listing prices, including NFT marketplaces, collection pages, and trading platforms. It automatically detects the marketplace and listing prices from page content. The script runs on all websites as designated in its match patterns.

HOW TO USE

After installing the BotGentz extension, navigate to any NFT listing page. Click the NFT Marketplace Fee Calculator icon in your browser toolbar or use the keyboard shortcut (Alt+F). The panel will open. Click "Connect Wallet" to connect your real EVM wallet extension—this enables gas price detection. The tool will automatically detect the marketplace and listing price. Configure override settings if you want to manually specify the marketplace or custom fee percentages. Toggle gas cost estimation on or off and set the gas buffer percentage. The panel displays a complete fee breakdown including marketplace fees, creator royalties, gas costs, total cost for buyers, net proceeds for sellers, and fee impact percentage. Alerts are triggered when total fees exceed your configured threshold. Click "Copy Results" to copy the breakdown to your clipboard.

TECHNICAL SECTION — MARKETPLACE DETECTION AND FEE CALCULATION ENGINE

Unlike basic price calculators that only show the listing price, this tool uses a marketplace detection and fee calculation engine. It first identifies the marketplace platform from the URL, hostname, or page content using a database of known marketplaces with their standard fee structures. The engine then detects the listing price from the page DOM using multiple strategies. For gas estimation, the tool fetches current gas prices from your connected wallet and applies a configurable buffer to account for price volatility. The engine calculates all costs using a comprehensive formula: total cost = listing price + (listing price × marketplace fee) + (listing price × royalty fee) + gas cost. Seller proceeds = listing price - (listing price × marketplace fee) - (listing price × royalty fee). Results are displayed in a clear breakdown with ETH formatting, and an alert system flags transactions where fees exceed a user-defined percentage threshold. This approach provides complete cost transparency for both buyers and sellers.

THE PANEL

The panel is draggable anywhere on the screen and remembers its position per site. It can snap to the left, right, top, or bottom edges, or float freely. Collapse it to a small status indicator when you need more page visibility, and expand it again with a single click. Resize it vertically or horizontally to show more of the fee breakdown. Press Escape to close the panel instantly. All settings (marketplace override, custom fees, gas inclusion, gas buffer, alerts, alert threshold) are saved globally and persist across sessions.

PLEASE NOTE

This tool requires the free BotGentz extension and a real EVM wallet extension already installed in your browser. EVM chains only—supports Ethereum Mainnet, Polygon, Arbitrum, and Optimism. Wallet connection is read-only; this tool never initiates transactions or signs messages. Cannot detect marketplace fee structures that are not publicly known or visible on the page, cannot accurately estimate gas costs without simulating the transaction, cannot detect dynamic fees that change based on user activity, and cannot identify hidden fees not disclosed in the marketplace's standard fee structure. Users must manually verify fee calculations before making any transaction decisions. Fee estimates are approximations; actual fees may vary based on network conditions and marketplace policies. Websites change their layouts frequently; scripts may need updates, and we work to keep them current but cannot guarantee uninterrupted operation.