what is the formula to convert light years to kilometers

A light year is the DISTANCE light travels in one year.  If you have Light Year in MILES units you can conver to KILOMETERS by multiplying by 1.609344

A light year in Kilometers is: 299,792.458 X 60seconds X 60 minutes X 24 hours X 365days

=9,454,254,955,488 Kilometers in 1 Light Year.