Pipe Size Decimal OD Metric OD
--------- ---------- ---------
1" 1.315" 33.40 mm
1-1/4" 1.660" 42.16 mm
1-1/2" 1.900" 48.26 mm
2" 2.375” 60.32 mm
Is PVC Pipe size ID or OD?
PVC Pipe is identified by the ID (Inside Diameter) and is referred to as a "nominal" size which means "in name only." However this confuses people and most novices try to use the OD (Outer Diameter) to order parts.