How Old Is J.? J. Birthday
J. was born in 1946 and is 78 years old now.
Birthday: 1946
How Old - Age: 78
J. Death Fact Check
J. is alive and kicking and is currently 78 years old.
Please ignore rumors and hoaxes.
If you have any unfortunate news that this page should be update with, please let us know using this form.
J. - Biography
Johannes "Hans" van Leeuwen (born 1946 in Gouda) is a Dutch-American professor of Civil, Construction and Environmental Engineering at Iowa State University and an entrepreneur.