We have developed an add‐on tool for use with the Agricultural Conservation Planning Framework (ACPF) that features a multistate financial analysis and field‐scale nitrogen (N) reduction tool for use when analyzing different ACPF conservation scenarios. Financial and expected field‐scale N loss data are used to calculate total long‐term cost and cost effectiveness of various conservation plans. Unique to the ACPF Financial and Nutrient Reduction Tool is the ability to identify individual treatment areas for each practice evaluated, allowing users to create combinatorial conservation planning scenarios drawing from multiple ACPF‐identified conservation practices. Financial data account for direct long‐term annualized costs for best management practice (BMP) installation and management in Iowa and Minnesota. Opportunity costs of BMPs that retire cropland are spatially determined according to weighted‐average crop productivity indices and land rent relationships. The tool quantifies the N requirements for each field, based on 6‐yr land‐use data, and evaluates the proportion of N likely to be lost from the field as nitrate load via leaching. Financial analyses that can be accomplished by using the ACPF are illustrated in case study watershed scenarios in Iowa and Minnesota. In Iowa, featured scenarios range from 26 to 31% reduction in total nitrate, for a total cost between US$0.580 million and $2.3 million per year, respectively. In Minnesota, example scenarios range from 28 to 51% total nitrate reduction, for total costs of $1.7 million to $2.1 million per year. Tradeoffs in BMP selection related to N reduction outcome and cost are also demonstrated.