Serving sizes are surely going to vary greatly from dog to dog. My 27lb dog eats this twice a day and eats about 2 cups or so day. Ultimately, I would potentially check with your vet or keep a close eye on your dog’s weight for the first month or so to make sure they are staying at the right weight and getting the right serving size.

Some serving size guidelines from http://www.dogaware.com/articles/wdjhomemade3.html:

As a general rule, dogs will eat around 2 to 3 percent of their body weight in fresh food daily (use cooked weights for foods that are cooked). Large dogs will tend to eat a lower percentage, and small dogs a higher percentage of their body weights. Toy breeds may need as much as 4 to 5 percent of their body weight daily, while giant breeds might eat as little as 1½ percent, or even less. I might start with around 2 pounds of food a day for a 100-pound dog (2 percent of their body weight), 1 to 1½ pounds of food for a 50-pound dog (2 to 3 percent of body weight), ½ to ¾ of a pound (8 to 12 ounces) of food for a 25-pound dog (2 to 3 percent of body weight), and 5 to 6½ ounces of food for a 10 pound dog (3 to 4 percent of body weight). When making your calculations, remember that ounces are not the same as tenths – 1.5 pounds is not 21 ounces (1 pound 5 ounces), it is 24 ounces (1.5 * 16).