Use this useful tool to convert charge volume density choosing one of the 6 units of measurment included in this app (with the availability to add custom units), that are:
coulomb/cubic meter, coulomb/cubic centimeter, coulomb/cubic inch, abcoulomb/cubic inch, abcoulomb/cubic meter, abcoulomb/cubic centimeter.
For every units of measurment are also included formulas to convert that unit as you want.