This study focused on mapping the volume and composition of avoidable food waste in the Finnish food production–consumption chain, and demonstrated that around 130 million kg of food waste are generated each year (23 kg per capita/year) from the household sector. Most of the discarded food was fresh and perishable, or leftovers from cooking and dining. Converted into greenhouse gases, the food discarded annually from Finnish households is approximately equal to the annual carbon dioxide emissions of 100,000 cars. The annual economic value of household food waste is about €70 per person. In the food service sector, the amount of waste ranged from 7% to 28% for cooked food, depending on restaurant type. In the entire sector it was estimated to be 75 to 85 million kg per year. Food waste was estimated to be 65–75 million kg per year in the retail sector. The entire food industry was estimated to produce around 75–140 million kg of food waste per year. Altogether, 335–460 million kg of food is avoidably wasted in the Finnish food chain (excluding primary production) per year.