Steel Pipe Weight Calculations: Schedule 40 & 80 Pipes

Steel pipes are used for structural framing, piling, and fluid transmission. Sizing is typically designated by Nominal Pipe Size (NPS) and Schedule (wall thickness), which require standard charts to find the exact dimensions.

Nominal Size vs. Actual Outer Diameter

For pipes under 14 inches, the nominal size does not match the actual outer diameter. A 4-inch Schedule 40 pipe has an outer diameter of 4.5 inches (114.3 mm) and a wall thickness of 0.237 inches (6.02 mm). These dimensions must be confirmed using a standard dimensions chart.

Weight Formulas

Once you have the outer diameter ((OD)) and wall thickness ((t)), the cross-sectional metal area can be calculated. The weight per unit length is then estimated by multiplying this area by the steel density.

Determine pipe weights using our interactive length to weight steel calculator. For comparison with alternative alloys, read our guide on carbon steel vs stainless steel weight.