Quite often moving boxes will have information on them, i.e. 4.5 cu ft meaning 4 and a half cubic feet. If you have a load of boxes the same size, multiply the amount of boxes by 4.5.
If you have a range of box sizes then stack them into a giant cube and measure the longest, widest and highest points of your cube in inches. Multiply these three dimensions together and then divide that number by 1728 and that will be your volume.
Another idea if you’re going to use a U Box or a crate, is to measure out the dimensions with blue masking tape on your floor and wall and make yourself an imaginary box and see if everything you have will fit into that space.
We also have an automatic volume estimator, where you can click on items you would like to take and it adds up the volume for you. We also have a handy tool, our volume calculator, here where you can enter the dimensions of an item and it will tell you the cubic volume.