Not done it but should be fairly easy to take a good stab at it, we would need to know:
What this one can kit weighed ? looks like its a 1.8kg can
then
What did you add to it - ie sugar, dried or liquid malt extract, and what weight ?
What volume did you mix this all to includng the water you added - ie, 19l, 22l, 23l
Oh and what is your finishing gravity reading that you have measured ?