The nominal weight of a steel pipe is calculated from its outside diameter and wall thickness: W = 0.0246615 × t × (D − t) kg per metre, where D is the outside diameter in millimetres and t is the wall thickness in millimetres, at a steel density of 7.85 g/cm³. Enter the size below.
Download PDF — Steel Pipe Weight Chart
| NPS 6 · SCH 40 · m | 28.264 kg/m |
|---|---|
| Weight per foot | 8.615 kg/ft |
| Weight per foot (pounds) | 18.992 lb/ft |
| Outside diameter | 168.30 mm |
| Wall thickness | 7.11 mm |
| Inside diameter | 154.08 mm |
| Total for this order | 169.6 kg |
Nominal (theoretical) weight. Actual weight varies with the mill tolerances allowed by the specification, and end preparations, couplings, thread protectors and coatings add to the shipping weight. Use this figure for estimating, not for a shipping manifest.
Source: nominal weight calculated from W = 0.0246615 × t × (D − t) kg/m at a density of 7.85 g/cm³ for carbon and low-alloy steel.
The formula, and why it works
A steel pipe is a cylinder with the middle removed. The cross-sectional area of the steel is π/4 × (D² − d²), where D is the outside diameter and d is the inside diameter. Because d = D − 2t, that area simplifies to π × t × (D − t). Multiply by the density of steel and you have the mass per unit length.
0.0246615 is simply π × 7.85 ÷ 1000, so the constant already carries a density of 7.85 g/cm³ — the figure used for carbon and low-alloy steel. Stainless steel is slightly denser at about 8.00 g/cm³ for the 300 series, which is why the material list above changes the result. If you would rather not calculate by hand, the weights for the standard sizes are tabulated on the steel pipe weight chart and the wall thicknesses on the pipe schedule chart.
What the answer means when you buy
Pipe is bought and sold by weight as often as by length, and the two are connected by exactly this number. A theoretical weight and the weight on the weighing bridge can differ in either direction: wall thickness is made to a minus tolerance (about −12.5% on seamless pipe) and single-length weight is commonly quoted at −3.5% / +10%, so a tolerance figure is normally agreed before a large order is priced. If your enquiry is priced per tonne, keep the theoretical weight and the tolerance allowance separate in the specification.
Frequently asked questions
How do I calculate the weight of a steel pipe in kg per metre?
Multiply 0.0246615 by the wall thickness in millimetres, then multiply by the outside diameter minus the wall thickness, both in millimetres. For NPS 6 schedule 40 pipe, that is 0.0246615 × 7.11 × (168.3 − 7.11) = 28.26 kg/m.
How many metres are in one tonne of steel pipe?
Divide 1000 by the weight per metre. NPS 6 schedule 40 at 28.26 kg/m gives about 35.4 metres to the tonne. Heavier wall thicknesses mean fewer metres per tonne, which is why pipe is priced per tonne rather than per length.
Does the calculator work for seamless and welded pipe?
Yes. Weight depends only on outside diameter, wall thickness and density, so the same formula covers seamless, ERW, LSAW and SSAW pipe. Seamless, ERW and submerged-arc pipe of the same size and schedule have the same nominal weight.
Should I use the theoretical or the actual weight?
Use the theoretical weight for estimating and for enquiry pricing, because it is the figure everyone in the trade quotes from. The actual weight is confirmed by the mill certificate and the weighing at load port, and the difference is settled against the tolerance agreed in the contract.
Where to go next
- Line pipe and steel pipe – seamless, ERW, LSAW and SSAW to API 5L, ASTM A106, A53, A333, A335 and A312
- Casing and tubing (OCTG) – API 5CT well casing and tubing, J55 through P110 and Q125
- API 5L X65 pipe – grade page with chemistry, mechanical properties and size range
- ASTM A106 Grade B pipe – the high-temperature seamless grade most often quoted with these charts
- Steel pipe weight calculator – work out the weight of any size and wall thickness
- Pipe schedule chart – wall thickness for every schedule
- Steel pipe size chart – outside diameter, wall thickness and inside diameter
- Steel pipe weight chart – nominal weight per metre and per foot
- Product line card – the five product lines and the standards behind each, as a one-page PDF
- All resources and tools – the calculator, the charts and the downloadable PDFs in one place
Need a price for a specific size and grade? Send the standard and grade, the size and wall thickness, the quantity and the destination port. We reply with availability and pricing.
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