That's a hard call because we can't see the size of the wheels.
I gather you don't have a scale??
I found this on a website...but I think as this is a salad, you don't need to be precise...just figure how many it is to serve and what the serving sizes are for your wagaon wheels
Measuring pasta serving sizes
Serving eight for dinner and need to know how many cups of pasta a pound will make? Here are some general guidelines for measuring dry versus cooked pasta.
The general rule
Shapes may vary in size according to the manufacturer, so use these measurements as generalizations. 8 oz. uncooked small to medium pasta shapes = 4 cups cooked
(Examples: Elbow macaroni, medium shells, rotini, twists, spirals, wagon wheels, bow ties, mostaccioli, penne, ziti, radiatore, rigatoni)
8 oz. uncooked long pasta shapes = 1 1/2-inch diameter bunch = 4 cups cooked
(Examples: Spaghetti, angel hair, linguine, vermicelli, fettuccine)
8 oz. uncooked egg noodles = 2 1/2 cups cooked
A full hand = two cups
The Food Guide Pyramid defines 1/2 cup cooked pasta as one serving. If you compare your hand to a plate of cooked pasta with sauce, you'll find that you're probably eating two cups of pasta, which means you're getting three to four servings of low-fat, high carbohydrate pasta in a single meal, at least half the recommended daily amount of grain foods.
A quarter = two ounces dry spaghetti
Two ounces of dry long pasta bunched up in your hand, such as spaghetti, thin spaghetti, linguine or vermicelli, is about the same size as the diameter of a quarter. Two ounces of dry pasta yields about 1 cup of cooked pasta (two servings).
Thoreau said, 'A man is rich in proportion to the things he can leave alone.'