The Healthy Diet Basket (HDB) is a comparable standard of a healthy diet used to calculate the cost and affordability of a healthy diet (CoAHD), a new indicator of food security. Using food prices from 177 countries from the International Comparison Program, this study generates 2,039 least-cost healthy diets following the HDB, national food-based dietary guidelines (FBDG), and the EAT-Lancet reference diet. It compares the cost, nutritional, and environmental characteristics of these diets. The cost of the HDB averaged $3.32 in 2017, slightly lower than most FBDG. Macronutrients fell within the acceptable macronutrient distribution ranges, and the average mean adequacy ratio (MAR) of 15 micronutrients and protein was 94.2% for the HDB, close to the average MAR of 95.0% across FBDG. The HDB was closely aligned with WHO dietary recommendations. The carbon and water footprints of the HDB were equivalent to those of the EAT-Lancet reference diet.