How long butterflies live depends on many things and varies greatly. It depends on the size of the butterfly, the species of the butterfly, where it lives, and what time of year it became an adult. For example, if the butterfly is of the smaller version it will probably not live as long, but if it is a larger butterfly, it will live longer. Now of course the size of the butterfly is not going to be the only factor of how long a butterfly will live, but does attribute to it.
There is an average life span of a butterfly – it is usually about one month. Although the smallest butterflies that you can usually spot feasting on the flowers in your front yard will usually only live about one week. Mourning Cloaks, some tropical Heliconians, and Monarchs are some of the only butterflies that have an average life span of about nine months.
There is also a difference between how long a butterfly would live if it was not living in the wild and how long it will actually live. Butterflies in the wild are exposed to many predators like birds and other insects, so may not live as long as they are capable of.