Flies generally have a short lifespan that varies by species and environmental conditions:

• House flies typically live about 15 to 30 days. Their lifespan depends on temperature and living conditions, with warmer environments allowing them to develop faster and live longer. In this time, females can lay multiple batches of eggs, enabling rapid population growth

• Fruit flies tend to live longer than house flies, around 40 to 50 days. They also reproduce quickly, with a single female capable of producing hundreds of offspring during their lifespan

• Other fly species vary widely: some gnats live 7 to 10 days, while cluster flies can survive several months, especially if they overwinter indoors

In optimal conditions, some flies can survive up to two months, but the average house fly lifespan remains around 15 to 30 days. Their entire life cycle-from egg to adult-can take as little as a week to a month depending on environment

. Thus, most common flies you encounter live roughly from two weeks to a month, with fruit flies on the longer side and house flies averaging about a month.