I recommend using a kitchen scale to make uniform burger patties. It sounds like more work, but it's really easier than without the scale. First, place the scale in a gallon size zip-close bag, so that the raw meat doesn't touch the scale. Set a 4 or 4 1/2-inch ring or biscuit cutter on the covered scale and add 5 ounces of meat inside the ring. Press gently to spread the meat into a circle. Lift the cutter and then gently pick up the formed patty.
The burgers can be made in advance and kept covered in the refrigerator for up to 8 hours. The burgers can also be frozen. (See below for full freezer directions.) This recipe can be doubled or tripled without any difficulty, although you may need to cook the burgers in batches, depending on the size of your grill.