A medium egg is about the size of a one-quarter cup. That's the proper size for serving of dried fruit.
One-half cup is about the size of a billiard ball. A half-cup portion is a single serving of the following foods: cooked grains (such as oats or brown rice), dry cereal, raw fruit (canned, fresh or frozen), cooked vegetables, and cooked beans or legumes.
Don't have a measuring cup on hand? Then think of a baseball, which is about the same size. One cup of raw, leafy greens (like salad) counts as a serving of vegetables and one cup of milk counts as a single serving of dairy.
Fluid ounces are often harder to measure, especially when glasses and cups vary in size and shape. But 6 oz. of volume takes up about the same amount of space as a hockey puck, which is equivalent to one serving of 100% fruit or vegetable juice.
Estimate a 2-tablespoon serving size (which is equal to one serving of nuts, seeds or peanut butter) by picturing a ping pong ball.
Although most servings of meat, tofu and fish double or triple the standard serving size of 2-3 ounces, you can eyeball your protein portions by picturing a deck of playing cards.
One ounce. That's the proper serving size for a serving of cheese. You can estimate your portions knowing that one ounce of cheese is about the size of a pair of dice.