Solar mass

If we define

Newton’s gravitational constant $G=1$,
Speed of light $c=1$,

kg and meter is related through

$\frac{G}{c^2} = 1,$

which is equivalent to

$7.425\times 10^{-28} \mathrm{m}\mathrm{kg^{-1}} = 1.$

Using this relation we find that

$1 \mathrm{kg} = 7.425\times 10^{-28} \mathrm{m}.$

In SI units, we know that solar mass is $1.988\times 10^{30}\mathrm{kg}$ and the mass of Earth is $5.972\times 10^{24}\mathrm{kg}$. The consersion to meters is straight forward.

By the way, the value of mass in length (meters) is called geometrized value.