It is not essential to choose small towel rails for small bathrooms. In fact, you might find that larger towel radiators make for a better addition for a compact space; they can act as somewhat of a focal point and provide an eye-catching wall feature.
The likes of ladder style heated towel rails are a sizeable type that will offer ample storage room for towels in a busy but diminutive family bathroom, for instance. That said, there is no set rule, and provided a bathroom towel radiator offers an adequate heat output for what you want it to achieve, you can decide on a small, large or medium sized towel rail based largely on your own personal preference.
For a deeper insight, browse our blog, What are the best heated towel rails for small bathrooms?