Guppies usually live for one to three years. Some guppies can even live for up to five years, although it is rare. A guppy’s lifespan mostly depends on its genetics and its living conditions.
Guppies bought from pet stores tend to be inbred and thus, weaker and with shorter lifespans. Guppies bought from reputable, local breeders tend to be healthier and more robust.
To increase their lifespans, make sure your guppies are living comfortably. Keep them in groups and away from aggressive tankmates so they don’t get stressed or lonely. Make sure there is at least one gallon of water for each guppy in the tank.
Lastly, feed them a healthy diet and maintain their tank conditions regularly.