According to analyses, the Earth will be able to support life for another 0.5 to 2.3 billion years.

An excerpt from the article 25 facts about Earth

As hydrogen deposits in the solar core decrease, the star's brightness is expected to increase. In just over a billion years the sun will shine 10 percent brighter and in 3.5 million years it will shine 40 percent brighter. In such conditions, all surface water on the planet will evaporate and the Earth will turn into a hellishly hot and uninhabitable place.