What is the standard drain size for a tub?

The standard drain size for a tub is typically 1 1/2 inches in diameter. This size is widely accepted in plumbing systems as it allows for adequate drainage while minimizing the risk of clogs. A 1 1/2 inch drain effectively handles the flow of water from a tub, which can fill quickly and requires a larger drainage capacity compared to smaller drain sizes.

In residential plumbing, using a drain size that is too small can lead to slow drainage and potential water backup. Conversely, while larger drain sizes may be appropriate in certain contexts (such as in other plumbing fixtures or commercial applications), they are not standard for household tubs. Therefore, a 1 1/2 inch drain size strikes an appropriate balance between efficiency and practicality for tub installations.