The main factors you should consider when choosing shower stall size include the dimensions of your bathroom and your individual needs. You can only insert a shower that will fit within the boundaries of your current bathroom, unless you are building a whole new house or adding a new bathroom. You should also consider how large you need the shower to be for comfort, and how many interior storage shelves will be needed.
If you'll be adding a new shower to your existing bathroom, the most important factor when choosing a shower stall size is obviously the size of the area where the shower will go. It is possible, if you have the funds, that you could rearrange other aspects of the room to accommodate a new shower, but if you are trying to save money, you'll have to work with what you already have. There are space saving techniques you can use to make the most of a small space.
Limited bathrooms can benefit greatly from a corner shower stall. They fit in smaller areas, but allow you to make the most of the floor space. Interior storage can also help you get more from a small shower, since you can use shelves and baskets to hang shampoo, conditioner, body wash, and other toiletries when not in use.
Another factor you should consider when determining shower stall size is the price. Larger showers will typically be more expensive than smaller ones, especially if they are made from top of the line materials. You might be able to afford higher-grade building materials such as tile if you go with a smaller shower stall size overall.
Your own comfort and safely is also of importance when choosing a shower stall size. If you have trouble getting around and will be using a shower seat or something similar, a small shower might be in order. On the other hand, if you are larger in size, a bigger shower stall will be needed so you can maneuver and wash efficiently and comfortably.