The weight of a bathtub matters for installation and for your flooring. The installation is typically easier for a lighter bathtub because you can move it around as needed when connecting pipes, as well as for getting it from the front door to your bathroom. If you plan on putting your bathtub on an upstairs floor, keep in mind that your flooring will need to be able to support the weight of your bathtub, all of the water it holds, and yourself.