Article
Pipe weight is needed for freight, lifting plans, support design and costing. It can be worked out exactly from the outside diameter, the wall thickness and the density of the material.
The formula
For a pipe with outside diameter D and wall thickness t, both in millimetres, and a material density ρ in kg/m³:
Weight (kg/m) = π × (D - t) × t × ρ / 1,000,000
The term (D - t) is the mean diameter of the wall. Multiplying by π gives the mean circumference, and multiplying by t gives the cross-sectional area of steel.
The shortcut for carbon steel
Carbon steel has a density of about 7,850 kg/m³. Putting that into the formula gives the familiar shortcut:
Weight (kg/m) = (D - t) × t × 0.02466
Worked example: carbon steel
A 4 inch Schedule 40 pipe has an outside diameter of 114.3 mm and a wall of 6.02 mm.
(114.3 - 6.02) × 6.02 × 0.02466 = 108.28 × 6.02 × 0.02466 = 16.07 kg/m
That agrees with the published figure for 4 inch Schedule 40 in ASME B36.10.
Other materials
Use the density of the material in the full formula, or multiply the carbon steel result by the ratio of densities.
| Material | Density, kg/m³ (approx.) | Factor vs carbon steel |
|---|---|---|
| Carbon steel | 7,850 | 1.000 |
| Stainless steel 304 / 304L | 7,930 | 1.010 |
| Stainless steel 316 / 316L | 7,980 | 1.017 |
| Duplex 2205 | 7,800 | 0.994 |
Worked example: stainless steel
A 2 inch Schedule 40S pipe in 316L: outside diameter 60.3 mm, wall 3.91 mm.
π × (60.3 - 3.91) × 3.91 × 7,980 / 1,000,000 = 5.53 kg/m
Why the weighbridge disagrees
The calculation gives a theoretical weight. Real pipe differs because of mill tolerance on wall thickness (ASTM pipe standards allow the wall to be 12.5% under nominal, and some allow it over), tolerance on diameter, bevelled ends, and the actual density of the heat. For estimates and freight, the theoretical weight is the right number. For a binding weight, use the weight recorded against the actual consignment.
Use the calculator
Our free weight calculator does this for pipe, plate, round and hexagonal bar, and hollow sections, across sixteen materials, in metric and imperial units. See also pipe schedules explained.
Frequently asked questions
What is the formula for carbon steel pipe weight?
Weight (kg/m) = (OD − WT) × WT × 0.02466, with OD and wall thickness in mm.
Is stainless pipe heavier than carbon steel?
Slightly. Austenitic stainless is about 1–2% denser, so a factor of around 0.0249 is commonly used.
Why calculate pipe weight?
For freight planning, quotation by tonnage and structural load calculations.
Key takeaways
- Carbon steel: (OD − WT) × WT × 0.02466 kg/m.
- Adjust the factor slightly for stainless steel.
- Use actual OD and wall thickness, not nominal size.
Need these products?
Sawariya Metal Industries supplies stainless steel pipes, flanges and buttweld pipe fittings from Mumbai to buyers in India and overseas. Send your size, grade, standard and quantity through our enquiry form and we will reply with a clear quotation and the test documents you need. You can also browse our stainless steel pipes, flanges and buttweld fittings.