Pipe schedule chart and pipe weight calculator

lb/ft = 10.69 × (OD − t) × t

Outside diameter, wall thickness and weight of carbon steel pipe by nominal pipe size (NPS) and schedule, per ASME B36.10M and B36.19M. Weight per foot = 10.69 × (OD − t) × t, with OD and t in inches.

Pipe schedule chart: wall thickness and weight

Wall thickness in inches, weight in lb/ft. STD equals Sch 40 up to NPS 10; XS equals Sch 80 up to NPS 8.

Each cell: wall thickness (in) / weight (lb/ft). Data adapted from Wikipedia, "Nominal Pipe Size" (CC BY-SA 4.0), which reproduces ASME B36.10M-2015; STD, XS and XXS checked against the AISC Shapes Database.

How pipe weight is calculated

Plain-end weight per foot (lb/ft) = 10.69 × (OD − t) × t, where OD and t are in inches. In metric units, kg/m = 0.02466 × (OD − t) × t with OD and t in mm. Both come from the area of the pipe wall, π (OD − t) t, times the density of carbon steel.

Example: 4" Sch 40 has OD 4.500 in and a 0.237 in wall, so 10.69 × (4.500 − 0.237) × 0.237 = 10.80 lb/ft. The constant 10.69 is π × 12 in/ft × 0.2836 lb/in³. Threaded and coupled pipe is slightly heavier than plain end.

Common sizes: weight of a length

Carbon steel pipe is sold in single random lengths of about 21 ft (6.4 m) and double random lengths of about 42 ft; metric projects often order 6 m. The last columns are Sch 40 pipe filled with water, which is what pipe supports carry.

Nominal pipe size is not the outside diameter

Pipe sizes go back to the inside diameters of early wrought iron pipe. When walls got thinner and stronger, the outside diameter was kept so fittings still fitted, and the size became a name. Up to NPS 12 the outside diameter is larger than the nominal size: 1/2" pipe is 0.840 in (21.3 mm) outside, 2" is 2.375 in (60.3 mm) and 12" is 12.75 in (323.9 mm). From NPS 14 upward the outside diameter equals the nominal size. Metric drawings use DN, the nominal diameter in millimetres: DN 15 is 1/2", DN 50 is 2", DN 100 is 4".

Schedules, STD, XS and XXS

The schedule number sets the wall thickness for each size: the higher the schedule, the thicker the wall, while the outside diameter stays the same. Sch 40 and Sch 80 are by far the most common. Schedules with an S (5S, 10S, 40S, 80S) come from ASME B36.19M for stainless steel pipe. STD (standard), XS (extra strong) and XXS (double extra strong) are older weight classes that still appear on drawings. They match Sch 40 and Sch 80 only up to a point:

When a drawing says "STD" for a 12" line, order 0.375 in wall, not Sch 40 (0.406 in).