Depends how fast you are travelling and what point the Jupiters is in its orbit. When it is closest to the earth Jupiter is 628,743,036 million km away, but 928,081,020 million km when it is furtherest away.
So a long time!!
It is a hard question to answer as missions use different launch vehicles (rockets) and take different trajectories. Here are some jouney times of historical Jupiter missions.
Pioneer 10 launched March 1972, flew by Jupiter January 1974
Pioneer 11 launched April 1973, flew by Jupiter January 1975
Voyager 2 launched August 1977, flew by Jupiter August 1979
Voyager 1 launched September 1977, flew by Jupiter April 1979
Galileo launched October 1989, arrived at Jupiter in December 1995 (took long way via Venus and Earth)
Cassini launched October 1997, flew by Jupiter December 2000
New Horizons launched January 2006, flew by Jupiter February 2007 (fastest spacecraft ever)
Good to see New Horizons got there faster. Means we are getting better. As far away as jupiter is, it is still not very far away when compared to the size of the whole solar system… Try the planetary walk at Armagh observatory, and you will get an idea!