A buyer orders 200 pipes for a plumbing and fire line. The quote is per kg, the truck arrives, and the invoice is far higher than the estimate. Nothing was wrong with the pipes. The estimate simply used the wrong wall thickness.
Pipe weight is what you pay for, so it pays to know it before you order. This chart gives you weight per metre for common MS and GI pipe sizes, the formula behind it, and a simple way to check your delivery.
Quick answer: Steel pipe weight per metre = (OD − wall thickness) × wall thickness × 0.02466, with both measurements in mm. A 50 NB medium class GI pipe (60.3 mm OD, 3.6 mm wall) weighs about 5.03 kg per metre, so a 6 m length weighs roughly 30 kg. Wall thickness changes the weight far more than most buyers expect.
Pipe Weight Chart (15 NB to 100 NB)
Weights below are calculated from the formula for light, medium and heavy class pipes. Each cell shows wall thickness in mm, then weight in kg per metre.
| Nominal bore (NB, mm) | Outer diameter (mm) | Light: thickness / kg per m | Medium: thickness / kg per m | Heavy: thickness / kg per m |
|---|---|---|---|---|
| 15 | 21.3 | 2.0 / 0.95 | 2.6 / 1.20 | 3.2 / 1.43 |
| 20 | 26.9 | 2.3 / 1.40 | 2.6 / 1.56 | 3.2 / 1.87 |
| 25 | 33.7 | 2.6 / 1.99 | 3.2 / 2.41 | 4.0 / 2.93 |
| 32 | 42.4 | 2.6 / 2.55 | 3.2 / 3.09 | 4.0 / 3.79 |
| 40 | 48.3 | 2.9 / 3.25 | 3.2 / 3.56 | 4.0 / 4.37 |
| 50 | 60.3 | 2.9 / 4.10 | 3.6 / 5.03 | 4.5 / 6.19 |
| 65 | 76.1 | 3.2 / 5.75 | 3.6 / 6.44 | 4.5 / 7.95 |
| 80 | 88.9 | 3.2 / 6.76 | 4.0 / 8.37 | 4.8 / 9.95 |
| 100 | 114.3 | 3.6 / 9.83 | 4.5 / 12.18 | 5.4 / 14.50 |
These are theoretical weights from the formula. Published standard tables, such as IS 1239 for GI pipes, can differ by a small margin, and GI pipes weigh a little more than plain MS pipes of the same size because of the zinc coating. Always confirm the exact thickness and weight with your supplier before you place the order.
The Formula: Weight per Metre
The same formula works for any round MS or GI pipe, including sizes not in the chart:
Weight (kg/m) = (OD − t) × t × 0.02466
OD is the outer diameter in mm and t is the wall thickness in mm. For example, a 60.3 mm OD pipe with a 3.2 mm wall gives (60.3 − 3.2) × 3.2 × 0.02466, which is about 4.51 kg per metre.
How to Turn This Into an Order
- Fix the size and thickness first. Write the outer diameter or nominal bore and the wall thickness or class on the purchase order. “2 inch pipe” is not enough.
- Multiply by length. A 6 m length of 50 NB medium pipe weighs about 5.03 × 6 = 30.2 kg.
- Find the pieces per tonne. Divide 1000 by the weight of one length. For the same pipe, that is about 33 pipes per tonne.
- Add wastage. Add 2 to 3% for cutting if you are fabricating from standard lengths.
Check the Weight on Delivery Day
- Measure the outer diameter and the wall thickness with a vernier caliper on a few pipes from different bundles.
- Compare the thickness with what you ordered. Thin walls are the most common reason weight comes in short.
- Weigh a sample bundle, or check the weighbridge slip against the calculated weight.
- Keep the test certificate or invoice details with the batch for your records.
Common Mistakes When Ordering Pipes by Weight
- Ordering by size only. A 50 NB light pipe and a 50 NB heavy pipe differ by about 2 kg per metre. Over 100 lengths of 6 m, that is more than a tonne. See our guide to GI pipe classes.
- Mixing up nominal bore and outer diameter. A 50 NB pipe has an outer diameter of 60.3 mm, not 50 mm.
- Comparing per-kg rates without checking thickness. The cheaper quote may simply be a thinner wall.
- Choosing the wrong pipe type. Not sure whether you need MS or GI? Read MS pipes vs GI pipes and ERW vs seamless pipes.
Buying other sections too? See our TMT bar weight chart and MS angle, channel and beam weight chart.
Frequently Asked Questions
What is the weight of a 1 inch GI pipe per metre?
A 25 NB (1 inch) medium class pipe weighs about 2.41 kg per metre. Light class is about 1.99 kg and heavy class about 2.93 kg.
How do I calculate the weight of an MS pipe?
Use (OD − thickness) × thickness × 0.02466 for kg per metre, with both values in mm. Multiply by the length in metres for the total.
How many 6 m pipes are in one tonne?
It depends on the size and wall. For 50 NB medium class, about 33 pipes make one tonne. For 25 NB medium class, it is about 69 pipes.
Why does the same pipe size have different weights?
Because the wall thickness changes by class. Light, medium and heavy pipes share the same outer diameter but have different wall thicknesses.
Is GI pipe heavier than MS pipe?
Slightly, for the same size and wall, because of the zinc coating.
Need Steel Pipes in Bhavnagar or Surat?
Tell us the pipe type, outer diameter or nominal bore, wall thickness or class, length and quantity, and we will confirm availability and weight before you place the order. See our steel pipes supplier page or read what local stock means for your project.
