like human dogs have also have different growth rate and muscle build. i have never seen two dogs who have same growth rate. you can prepare your own chart and keep tracking your boy.
make sure your dogs eyes looks bright,
coat looks good,
no weakness sign in rear and anus area always should look clean.
for weight there is no fixed dose of food you have to feed... feed you dog well... make sure you cant see your dog's ribs but can feel it with your finger when you rub his ribs area...
in case of any big variation in his growth record please visit your vet