Hubble calculated a value for
H0 of about 500 km. s-1. Mpc-1. (1 Mpc-1 is 1 megaparsec or about 3.26 million light years. Astronomers use the parsec as the unit of distance measure rather than the light year. Details about the
parsec can be found in the Year 12 Astrophysics topic). This value results in an age of the Universe of 2 × 109 years, that is 2 billion years.
Even in Hubble's day this age proved problematic as it clashed with radiometric dating values for the age of the Earth that ranged from 3 to 5 billion years and other evidence on the age of stars. Obviously this posed a dilemma - the Universe could not be younger than the stars or planets it contained! The problem was eventually resolved in the 1950s when the recalibration of the Cepheid period-luminosity relationship provided an age for the Universe in the range of 10-20 billion years.
Even today astronomers spend a lot of time trying to determine a more precise and accurate value for
H0 and thus also an age for the Universe.