# Geometrized Units

## Main Question or Discussion Point

Geometrized units use the multiplication factor to convert for example mass to length, in this case the factor would is G/C^2. I know this is to do with setting c=G=1. How does one derive the multiplication factor from this?

Any help greatly appreciated.

Shane

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Ich
You have
c = 1 = 3e8 m/s, therefore 1 s = 3e8 m
G = 1 = 6.67e-11 m³/(kg*s²) = 6.67e-11/(3e8)² m/kg, therefore 1 kg = 6.67e-11/(3e8)² m

Thank you Ich. I now see where G/c^2 comes from.

Similarily would you be able to show me where \sqrt(G/(4\pi\epsilon_0))^{1/2}/c^2 come from for converting Coulombs to length? I presume it has soemthing to do with the equation for either electric field or electric force as both these contain 4\pi\epsilon_0.

Thanks for your help so far.

Yes I have checked out wiki. Thank you. But there they only gave the multiplication factors but not where they came from. But I know where the factor for converting from Coulumbs to length comes from now. Thanks