Fruit and Vegetable Servings?

When a serving size is recommended for fruits and vegetables how are these serving sizes to be measured out. I believe the current recommendation is to eat 5-6 servings of fruits and/or vegetables a day. If not please correct me. Say I am going to eat an apple. Now that would be considered one serving correct? Say that I want to add some blueberries to my oatmeal for breakfast. How much would be considered a serving? Most fruits and vegetables don’t have food labels. Any help would be appreciated.

A serving is typically equal to the size of your clenched fist.

Otherwise, if you buy frozen or canned veggies, they do tell you how much a serving size is equal to (1/4 cup to 1 cup).

Serving size is usually measured by weight. For fruits, around 140 grams. For vegetables, 85 to 90 grams. Otherwise, read the labels if available.