What is the acceptable waste pipe size for a bathtub?

The acceptable waste pipe size for a bathtub is typically 1 1/2 inches. This size is standard in plumbing codes as it provides adequate drainage while minimizing the risk of clogs. A pipe diameter of 1 1/2 inches allows for the proper flow of wastewater, accommodating the volume generated by typical bathtub use, including the water and any soap or debris. Smaller sizes, like 1 inch or 1 1/4 inches, may not provide sufficient drainage capacity, leading to slow drainage or backups. Larger sizes, such as 2 inches, might be permissible in certain scenarios but are generally more than what is necessary for a bathtub installation, potentially resulting in increased material costs without added benefit. Thus, the choice of 1 1/2 inches balances efficiency and effectiveness in waste management for bathtubs.