[header] How to calculate the volume of an irregular object [title] Make sure the object is waterproof before you begin. [step] This method involves submerging the object in water. If the object is hollow and not watertight, you cannot get an accurate measure of volume using this method. 
If the object absorbs water, make sure water will not damage it, and read the instructions carefully to see how to adjust the process. Never drop an electric or electronic item in water, as this could cause a dangerous electrical shock and/or damage the object beyond repair.