Steel Round Bar Weight Calculator
Weight per metre and total weight of round, square and flat steel bar in kg — for EN24, EN47, EN353, EN36C, SAE 8620 and other alloy and carbon steels.
Round bar uses the trade formula D² × 0.00625 kg/m, which matches the weighed weight of our rolled and forged bars. Square and flat bar use the matching trade factor, 0.00796.
How to calculate steel bar weight
Steel bar weight is volume × density. With sizes in millimetres, these are the constants we use:
kg/m = D² × 0.00625kg/m = A² × 0.00796kg/m = W × T × 0.00796For round bar we use the trade formula D² × 0.0019 ÷ 304 × length in mm, which works out to D² × 0.00625 kg per metre. It matches the weighed weight of our bars — for example, a Ø220 mm bar 4,565 mm long weighs 220 × 220 × 0.0019 ÷ 304 × 4565 ≈ 1,381 kg. It is about 1.4% higher than the theoretical figure at 7.85 g/cm³ (D² × 0.00617) because bars are supplied slightly oversize.
Square and flat bar use the matching trade factor, 0.00796. Multiply kg/m by the length in metres, then by the number of pieces. Example: a Ø50 mm round bar is 50 × 50 × 0.00625 = 15.63 kg/m, so a 6 m bar weighs about 93.8 kg.
Steel round bar weight chart (kg per metre)
Weights using D² × 0.00625 kg/m, the formula that matches our weighed rolled and forged bars. The last column shows how many metres make 100 kg — our minimum order.
| Diameter | kg / metre | kg / 6 m bar | Length for 100 kg |
|---|---|---|---|
| Ø14 mm | 1.23 | 7.35 | 81.6 m |
| Ø16 mm | 1.60 | 9.60 | 62.5 m |
| Ø20 mm | 2.50 | 15.00 | 40.0 m |
| Ø25 mm | 3.91 | 23.44 | 25.6 m |
| Ø28 mm | 4.90 | 29.40 | 20.4 m |
| Ø32 mm | 6.40 | 38.40 | 15.6 m |
| Ø36 mm | 8.10 | 48.60 | 12.3 m |
| Ø40 mm | 10.00 | 60.00 | 10.0 m |
| Ø45 mm | 12.66 | 75.94 | 7.9 m |
| Ø50 mm | 15.63 | 93.75 | 6.4 m |
| Ø56 mm | 19.60 | 117.60 | 5.1 m |
| Ø63 mm | 24.81 | 148.84 | 4.0 m |
| Ø70 mm | 30.63 | 183.75 | 3.3 m |
| Ø75 mm | 35.16 | 210.94 | 2.8 m |
| Ø80 mm | 40.00 | 240.00 | 2.5 m |
| Ø90 mm | 50.63 | 303.75 | 2.0 m |
| Ø100 mm | 62.50 | 375.00 | 1.6 m |
| Ø110 mm | 75.63 | 453.75 | 1.3 m |
| Ø125 mm | 97.66 | 585.94 | 1.0 m |
| Ø140 mm | 122.50 | 735.00 | 0.8 m |
| Ø150 mm | 140.63 | 843.75 | 0.7 m |
| Ø160 mm | 160.00 | 960.00 | 0.6 m |
| Ø180 mm | 202.50 | 1,215.00 | 0.5 m |
| Ø200 mm | 250.00 | 1,500.00 | 0.4 m |
| Ø205 mm | 262.66 | 1,575.94 | 0.4 m |
| Ø220 mm | 302.50 | 1,815.00 | 0.3 m |
| Ø250 mm | 390.63 | 2,343.75 | 0.3 m |
| Ø280 mm | 490.00 | 2,940.00 | 0.2 m |
| Ø315 mm | 620.16 | 3,720.94 | 0.2 m |
Square bar weight chart
| Size | kg / metre | kg / 6 m |
|---|---|---|
| 16×16 mm | 2.04 | 12.23 |
| 20×20 mm | 3.18 | 19.10 |
| 25×25 mm | 4.98 | 29.85 |
| 32×32 mm | 8.15 | 48.91 |
| 40×40 mm | 12.74 | 76.42 |
| 50×50 mm | 19.90 | 119.40 |
| 55×55 mm | 24.08 | 144.47 |
Flat bar weight chart
| Size | kg / metre | kg / 6 m |
|---|---|---|
| 28×36 mm | 8.02 | 48.14 |
| 36×45 mm | 12.90 | 77.37 |
| 45×55 mm | 19.70 | 118.21 |
Square and flat sizes shown are the EN47 sizes we stock.
Frequently asked questions
How do you calculate the weight of a steel round bar?
Weight in kg = D² × 0.0019 ÷ 304 × length in mm, where D is the diameter in mm — the same as D² × 0.00625 kg per metre. For example, a 50 mm round bar weighs 50 × 50 × 0.00625 ≈ 15.6 kg per metre.
What is the weight of a 1 metre 50 mm steel round bar?
About 15.6 kg using D² × 0.00625 (15.4 kg at the theoretical 7.85 g/cm³). A 6 metre length weighs about 93.8 kg.
What density is used for alloy steel?
7.85 g/cm³ (7,850 kg/m³) is the standard figure for carbon and low-alloy steels such as EN24, EN47, EN353, EN36C and SAE 8620. Because bars are supplied slightly oversize, we use trade factors that match weighed bars: D² × 0.00625 kg/m for round bar and 0.00796 for square and flat bar — about 1.4% above the theoretical figure.
How do you calculate the weight of a square or flat bar?
Square bar: side × side × 0.00796 kg per metre. Flat bar: width × thickness × 0.00796 kg per metre, with all sizes in mm.
Why can the actual weight differ from the calculated weight?
Bars are supplied with a size tolerance and are usually slightly oversize, which is why our formulas are about 1.4% above the theoretical weight. Invoiced weight is the actual weighed weight, so treat the result as a close estimate.
How many metres of bar make 100 kg?
Divide 100 by the kg per metre. For a 50 mm round bar that is 100 ÷ 15.63 ≈ 6.4 metres. Our minimum order is 100 kg, and the calculator shows how close your quantity is.
Need alloy steel round bar in Mumbai?
EN24, EN47, EN353, EN36C and SAE 8620 from ready stock at Darukhana. Minimum order 100 kg, mill test certificate with every dispatch.