Retailers increasingly stimulate their suppliers to reduce the environmental impact of agricultural production. The environmental impact resulting from producing a commodity can be measured with a Life Cycle Analysis (LCA) but performing an LCA is costly and time-consuming. We have developed a practical and generic tool to identify sustainability hotspots in crop production on a global scale. The tool was implemented in first instance for potatoes. The objective of the work reported here was to evaluate the hotspot tool and to identify improvement opportunities for each of seven indicators: low yield, erosion risk, nitrogen surplus, depletion of water reserves, biocide use, carbon footprint, and impact on biodiversity. The tool produces realistic outputs. We discuss ways to identify target values for indicators and argue that the tool can be used to target efforts that aim to improve the use efficiency of limited resources. The tool can be expanded to produce similar results for other crops. We discuss methods to improve the resolution of the tool.