NLET (National Load Estimating Tool), a component of the USDA/ARS Soil and Water Hub, is a web-based tool for estimating pollutant loads in watersheds across the contiguous United States. This tool helps visualize the effects of land use patterns, cultivated crops, and conservation practices through graphical representation. Visualizations illustrate baseline and scenario land-use, crops, conservation, runoff, sediment, nitrogen, and phosphorus, and load differences at 50th percentile. NLET implements an export coefficient approach for predicting the pollutant loads. NLET also addresses the need for a user-friendly, reliable and cost-effective watershed modeling tool. NLET utilizes the D3.js library for creating an open-source JavaScript and data-driven charts, as well as Mapbox and OpenStreetMap for the Leaflet library, another open-source JavaScript library used for displaying the locations of Hydrologic Unit Catalog (HUC).