What is the standard drain size for urinals?

The standard drain size for urinals is typically 2 inches in diameter. This size is adequate to handle the flow of wastewater that urinals generate, ensuring proper drainage without risk of clogs. The 2-inch diameter strikes a balance between allowing efficient drainage and fitting within standard plumbing practices. In plumbing codes, this size is commonly specified for urinals to maintain consistent standards across installations, facilitating effective drainage while minimizing potential for blockage. Other sizes, such as 1 inch, 3 inches, or 4 inches, may not be suitable for urinal applications either due to insufficient flow capacity or being unnecessarily large for the typical amount of waste produced by urinals.