I know the entire "deck of cards" thing, but is there an accurate cup measurement for 3 oz of ground beef?
The only way to accurately measure meats is by weight, not cup. I bought myself a nice digital scale at Bed, Bath and Beyond. It costs $29.00 but I had a 20% off coupon, so it wasn't bad and it's probably the best money I ever spent.
It's really hard to measure. I measure out my meat before I cook it. Ground beef should be measured before cooking if you purchase it in a tube with the nutritional facts on the dealy.
Thing is, the fat % of the beef is also going to change the yield of the cooked product. I eat 4oz extra lean 96/4% ground beef, and it yields about a cup. If it's fattier meat, it will be less.
And yes, a food scale will save you the hassle! Because believe me, without one, your deck of cards grows or shrinks depending on your level of appetite.