DEX Trade Size Impact Calculator

WHAT IT DOES

DEX Trade Size Impact Calculator monitors the current DEX swap page for the trade amount and token pair, reads pool reserves from the chain, and calculates the price impact of the trade at multiple sizes — current (1x), 2x, 5x, and 10x. For each size, it displays the impact percentage and estimated output, helping you understand how larger trade sizes affect the price you receive. The tool also provides a visualization showing the impact curve, making it easy to see the relationship between trade size and price impact at a glance.

WHERE IT RUNS

This userscript runs inside major DEX platforms including Uniswap, 1inch, SushiSwap, and PancakeSwap in your browser, powered by the free BotGentz extension. It operates entirely on the page you are viewing — it reads the swap state from the page and optionally reads on-chain pool reserves through your wallet provider. The tool is read-only and only displays calculations, never signing transactions or moving funds.

HOW TO USE

Install the BotGentz extension, then install this userscript from the BotGentz catalogue. Navigate to a swap page on Uniswap, 1inch, SushiSwap, or PancakeSwap. Connect your wallet (MetaMask or any EVM-compatible wallet) — the tool uses your wallet to read on-chain pool data. The tool automatically detects your trade amount and token pair from the page. Configure your settings — toggle the impact curve display, customize trade size multipliers (as a JSON array, e.g., [1,2,5,10]), and toggle highlighting of the recommended size, price impact display, and gas estimate. Click "Start Monitoring" to begin. The tool will calculate and display the impact for each trade size in a table, with a color-coded impact indicator and an impact curve chart.

HOW IT WORKS UNDER THE HOOD

The tool extracts the trade amount and token pair from the page's DOM. It reads pool reserves from the chain (simulated here for demonstration) using the token addresses. The price impact for each trade size is calculated using the constant product formula: output = (reserveOut * amountIn) / (reserveIn + amountIn). The impact percentage is derived from the difference between the current price and the effective price after the trade. For each configured size multiplier, the tool calculates the adjusted trade amount, computes the impact, and displays the results. The impact curve is drawn on a canvas element, showing the relationship between trade size and impact percentage. All calculations are performed locally and updated in real time as the trade amount changes.

THE PANEL

The tool runs in the BotGentz panel, a draggable floating interface that stays on top of the page. You can drag the panel by its header, collapse it to a small bubble, and resize it. The panel remembers its position per site, so it stays where you left it when you return to the DEX. Press Escape to close the panel when you are done. The panel includes a wallet connection button, a results table showing impact for each trade size, an impact curve visualization, settings for curve display, trade sizes, highlighting, price impact, and gas estimate, plus start/stop monitoring and manual calculate buttons.

PLEASE NOTE

This tool requires the free BotGentz extension and a real EVM wallet extension (MetaMask or similar) already installed in your browser. The tool works on EVM chains only — Ethereum, Polygon, Arbitrum, Optimism, BSC, and other EVM chains are supported. The tool is read-only and never signs transactions or moves funds. The price impact calculations are estimates based on current pool reserves and may not reflect final execution due to slippage, block timing, or MEV. DEX platforms frequently update their interfaces — if the tool stops working, check for an updated version or report the issue. Always verify impact calculations against the DEX's own estimates before executing large trades.