Kent Police said the man, from West Sussex, sustained a serious injury when his Ford Focus came off the road in Hoath Way on Friday.
He was taken to Medway Maritime Hospital but died on Saturday evening.
Police said the car left the carriageway before mounting a grass verge and overturning. No other vehicles were involved.
It is not yet known why the man lost control of his car.
A 67-year-old driver has died in hospital after he crashed his car in Gillingham.