Pipe weight calculation: formula, chart and worked examples

Pipe weight per metre depends on three things only: outside diameter, wall thickness and material density. Get those, and one formula gives you the answer for MS pipe, SS pipe or any hollow round section. Here is the maths, a schedule chart, and the mistakes that throw estimates off.

Whether you are raising an RFQ for structural pipe, checking a fabrication estimate, or sizing a crane lift, you need the weight per metre before anything else. The good news: a pipe is just a hollow cylinder, so the calculation is exact — no lookup table required once you know the formula.

The pipe weight formula

Start from the cross-sectional area of the pipe wall — a ring. For an outside diameter OD and inside diameter ID (both in mm):

The 10−6 converts mm² × (kg/m³) into kg/m over a one-metre length. That single equation works for every round pipe in any material — you only swap the density.

The steel shortcut

Because most engineers work in mild steel, the formula simplifies. Substituting ID = OD − 2t and steel density 7850 kg/m³, the whole thing collapses to a clean expression:

For stainless steel, swap the constant: SS 304/316 has a density near 8000 kg/m³, so use 0.02512 instead of 0.02466 — roughly 2% heavier than mild steel for the same size.

Worked example

Take a common 50 NB (2 inch nominal bore) Schedule 40 mild steel pipe: OD = 60.3 mm, wall t = 3.91 mm.

• OD − t = 60.3 − 3.91 = 56.39 mm
• Weight = 0.02466 × 3.91 × 56.39
• Weight = 5.44 kg/m

A 6 metre length therefore weighs about 32.6 kg. Cross-check against the exact ring formula: ID = 60.3 − 2(3.91) = 52.48 mm, area = (π/4)(60.3² − 52.48²) = 693 mm², × 7850 × 10⁻⁶ = 5.44 kg/m. Both agree.

Common MS pipe weight chart (Schedule 40)

These match the exact formula to within rounding. For non-standard sizes, plug OD and t straight into the steel shortcut.

Density values for other materials

The constant is simply π × density × 10⁻⁶. Multiply it by t × (OD − t) for the weight per metre in that material. To weigh solid bars, plates or other sections instead of pipe, use our material weight calculator, which handles every profile.

Common mistakes

• Confusing NB with OD. The single biggest error — always convert nominal bore to the real outside diameter first.
• Using ID instead of OD in the shortcut. The 0.02466 formula expects OD and t, not ID.
• Forgetting schedule. The same NB size has different wall thickness across Sch 40, Sch 80 and Sch 160 — weight can nearly double.
• Wrong density for stainless. Using the steel constant for SS underestimates weight by about 2%, which adds up on large orders.

Frequently asked questions

How do you calculate the weight of a steel pipe?

Use weight per metre = 0.02466 × t × (OD − t), with wall thickness t and outside diameter OD in millimetres. Multiply by the pipe length in metres for total weight.

What is the weight of a 2 inch (50 NB) MS pipe?

A 50 NB Schedule 40 mild steel pipe (OD 60.3 mm, wall 3.91 mm) weighs about 5.44 kg per metre, so a standard 6 m length is roughly 32.6 kg.

Does pipe weight change with material?

Yes. The geometry term stays the same but density changes: stainless steel is about 2% heavier than mild steel, aluminium is roughly one-third the weight, and copper is heavier than steel for the same dimensions.

How do I find pipe weight if I only know nominal bore?

Nominal bore alone is not enough — you also need the schedule, which sets the wall thickness and the true outside diameter. Look up the OD and t for that NB and schedule, then apply the formula.

Working on inspection paperwork for those pipes too? CadNexa can auto-balloon a PDF drawing and build the dimensional report in minutes.