What is the average size of an orange?

The average size of an orange is approximately 2.5 inches in diameter, though measurements vary between species. Countries that produce oranges include the United States, Mexico and Pakistan.

Oranges between 5 and 6 ounces contain about 80 calories. They also contain 250 milligrams of potassium, according to the U.S. Food and Drug Administration. Contrary to popular belief, orange peels are not poisonous; however, they may be covered in chemicals if they are not organically grown. The vitamin C content in oranges can strengthen a person's immune system and protect cells from free radicals that could lead to cancer and disease.