A workshop owner in Rajkot needed 1,200 metres of 20 mm MS round bar for a batch of shafts and fixtures. He ordered “3 tonnes” and assumed that would cover it. It did not. A 20 mm round bar weighs about 2.47 kg per metre, so 1,200 metres needs about 2,963 kg. He had room to spare on that order. But a second job, with 25 mm bar, used the same guess and fell short by almost half a tonne.
Round and square bars are sold by weight but cut and used by length. This chart helps you convert between the two before you place an order.
Quick answer: The weight of an MS round bar in kg per metre is diameter (mm) squared divided by 162. A 20 mm round bar weighs about 2.47 kg per metre, or about 14.8 kg for a 6 metre length. For a square bar, multiply the side (mm) squared by 7.85 and divide by 1,000. Use the charts below to find the weight per metre, the weight of a 6 m piece, and how many metres you get in one tonne.
MS Round Bar Weight Formula
Weight per metre (kg) = diameter (mm) x diameter (mm) / 162
Example: a 25 mm round bar weighs 25 x 25 / 162 = 3.86 kg per metre. For a 6 m piece, multiply by 6 to get 23.1 kg.
The same result comes from d x d x 0.00617. Both come from the density of mild steel, 7.85 grams per cubic centimetre. These are theoretical weights. Actual weight can differ slightly because of rolling tolerance.
MS Round Bar Weight Chart
| Diameter (mm) | Weight per metre (kg) | Weight of 6 m piece (kg) | Metres per tonne (approx.) |
|---|---|---|---|
| 6 | 0.22 | 1.3 | 4,500 |
| 8 | 0.40 | 2.4 | 2,531 |
| 10 | 0.62 | 3.7 | 1,620 |
| 12 | 0.89 | 5.3 | 1,125 |
| 16 | 1.58 | 9.5 | 633 |
| 20 | 2.47 | 14.8 | 405 |
| 25 | 3.86 | 23.1 | 259 |
| 32 | 6.32 | 37.9 | 158 |
| 40 | 9.88 | 59.3 | 101 |
| 50 | 15.43 | 92.6 | 65 |
| 63 | 24.50 | 147.0 | 41 |
| 75 | 34.72 | 208.3 | 29 |
| 100 | 61.73 | 370.4 | 16 |
MS Square Bar Weight Formula
Weight per metre (kg) = side (mm) x side (mm) x 7.85 / 1,000
Example: a 20 x 20 mm square bar weighs 20 x 20 x 7.85 / 1,000 = 3.14 kg per metre. A square bar is always heavier than a round bar of the same size, because it has more steel in the section.
MS Square Bar Weight Chart
| Size (mm) | Weight per metre (kg) | Weight of 6 m piece (kg) | Metres per tonne (approx.) |
|---|---|---|---|
| 8 x 8 | 0.50 | 3.0 | 1,990 |
| 10 x 10 | 0.79 | 4.7 | 1,274 |
| 12 x 12 | 1.13 | 6.8 | 885 |
| 16 x 16 | 2.01 | 12.1 | 498 |
| 20 x 20 | 3.14 | 18.8 | 318 |
| 25 x 25 | 4.91 | 29.4 | 204 |
| 32 x 32 | 8.04 | 48.2 | 124 |
| 40 x 40 | 12.56 | 75.4 | 80 |
| 50 x 50 | 19.62 | 117.8 | 51 |
These are theoretical weights for mild steel. Ask us for sizes that are not listed.
How to Use the Chart for Your Order
- Find your size in the first column.
- Work out the total length you need, in metres. Add 3 to 5 percent for cutting waste.
- Multiply the length by the weight per metre to get the total weight in kg.
- Convert to tonnes by dividing by 1,000, and use that figure in your enquiry.
Example: you need 300 pieces of 16 mm round bar, each 1.2 m long. Total length is 360 m. Weight is 360 x 1.58 = 569 kg. Add a small allowance for waste and ask for 600 kg.
What to Mention When You Ask for a Quote
- Shape and size: round diameter or square side, in mm.
- Length: standard length or cut-to-length. Tell us the length you need.
- Quantity: in tonnes or pieces.
- Grade or standard: for example IS 2062 for structural use. Say so if your drawing names a grade.
- Delivery location: city or site address.
Not sure what to include? Use our bulk steel quote checklist.
Related Weight Charts
Frequently Asked Questions
How do I calculate the weight of an MS round bar?
Square the diameter in mm and divide by 162. The result is the weight in kg per metre.
How much does a 12 mm MS round bar weigh?
About 0.89 kg per metre, or about 5.3 kg for a 6 metre length.
How many metres of 16 mm round bar do I get in one tonne?
Divide 1,000 by 1.58. That gives about 633 metres.
Is a round bar weight the same as a TMT bar weight?
The formula is the same, because both are steel. But TMT bars have ribs, so check our TMT bar weight chart for the standard figures.
Is the chart weight the same as the actual weight?
No. The chart gives theoretical weight. Actual weight can vary slightly because of rolling tolerance, so confirm the billing basis with your supplier.
Do you supply from Bhavnagar and Surat?
Yes. See our Bhavnagar and Surat pages.
Need MS Round or Square Bars? Get a Clear Quote
Send us the size, length, quantity and delivery location. We will confirm availability and come back with a clear quote.
Call 7226060911 or send your requirement below.
