What is the volume of a onion?

The volume of an onion can vary significantly based on its size and variety. On average, a medium onion has a volume of about 100 to 150 cubic centimeters (cc) or milliliters (ml). To calculate the volume more precisely, one could use the formula for the volume of a sphere or an ellipsoid, depending on the onion's shape. However, for practical purposes, measuring by displacement in water can also provide an accurate volume.