1 kg= 2.2 lbs. , 1 lb.=16 oz. You can break that down if you know the equivalents.
I just learned these in nursing school
xoz.=
16oz.x
2.2lb.x
1.9kg= 66.88oz. 66.88oz at 19 weeks

1lb. 1kg x
I will go look up the forecasted weight for your pup, be right back.