Steel angle weight depends on the two leg lengths and the thickness. A common L102x102x9.5 (4 x 4 x 3/8 in) weighs about 14.6 kg per metre (9.8 lb/ft), and you can estimate any angle with one formula: thickness x (leg A + leg B minus thickness) x 0.00785 = kg per metre, with all dimensions in millimetres. The charts below list published weights for the angle sizes used most in Ontario construction, followed by the formula, worked examples and the reasons your number may differ slightly from a supplier's.
The steel angle weight formula
An angle is two flat bars joined at a corner. If you add the area of both legs and subtract the square where they overlap, you get the cross-sectional area:
Area (mm²) = t x (a + b minus t)
where a and b are the leg lengths and t is the thickness, all in millimetres. Carbon steel weighs about 7,850 kg per cubic metre, which works out to 0.00785 kg per metre for every square millimetre of area. So:
Weight (kg/m) = t x (a + b minus t) x 0.00785
Example for an L76x76x6.4 (3 x 3 x 1/4 in):
- Area = 6.4 x (76 + 76 minus 6.4) = 6.4 x 145.6 = 932 mm²
- Weight = 932 x 0.00785 = 7.3 kg/m
The published value is also 7.3 kg/m. On larger and thicker angles the formula comes in a little under the table, because a rolled angle has a rounded fillet at the inside corner that adds a small amount of steel, and rounded toes that take a little away. The difference is usually around one percent.
For imperial units, the equivalent is: thickness (in) x (leg A + leg B minus thickness) (in) x 3.4 = lb per foot. The 3.4 comes from steel weighing about 0.2836 lb per cubic inch, multiplied by 12 inches per foot.
Our guide to calculating structural steel weight covers the same method for beams, tubes, bar and plate.
Equal-leg angle weight chart
Metric designations list leg, leg and thickness in millimetres. They are converted from the imperial sizes the angles are rolled to, which is why you see 102 mm rather than 100 mm.
| Metric designation | Imperial (in) | kg/m | lb/ft |
|---|---|---|---|
| L51x51x4.8 | 2 x 2 x 3/16 | 3.6 | 2.44 |
| L51x51x6.4 | 2 x 2 x 1/4 | 4.7 | 3.19 |
| L51x51x9.5 | 2 x 2 x 3/8 | 7.0 | 4.7 |
| L64x64x6.4 | 2-1/2 x 2-1/2 x 1/4 | 6.1 | 4.1 |
| L64x64x9.5 | 2-1/2 x 2-1/2 x 3/8 | 8.7 | 5.9 |
| L76x76x6.4 | 3 x 3 x 1/4 | 7.3 | 4.9 |
| L76x76x9.5 | 3 x 3 x 3/8 | 10.7 | 7.2 |
| L76x76x12.7 | 3 x 3 x 1/2 | 14.0 | 9.4 |
| L89x89x6.4 | 3-1/2 x 3-1/2 x 1/4 | 8.6 | 5.8 |
| L89x89x9.5 | 3-1/2 x 3-1/2 x 3/8 | 12.6 | 8.5 |
| L102x102x6.4 | 4 x 4 x 1/4 | 9.8 | 6.6 |
| L102x102x7.9 | 4 x 4 x 5/16 | 12.2 | 8.2 |
| L102x102x9.5 | 4 x 4 x 3/8 | 14.6 | 9.8 |
| L102x102x12.7 | 4 x 4 x 1/2 | 19.0 | 12.8 |
| L127x127x9.5 | 5 x 5 x 3/8 | 18.3 | 12.3 |
| L127x127x12.7 | 5 x 5 x 1/2 | 24.1 | 16.2 |
| L152x152x9.5 | 6 x 6 x 3/8 | 22.2 | 14.9 |
| L152x152x12.7 | 6 x 6 x 1/2 | 29.2 | 19.6 |
| L152x152x19 | 6 x 6 x 3/4 | 42.7 | 28.7 |
| L203x203x12.7 | 8 x 8 x 1/2 | 39.3 | 26.4 |
| L203x203x19 | 8 x 8 x 3/4 | 57.9 | 38.9 |
Values from the AISC Shapes Database (version 15.0, imperial and metric columns), rounded. Not every size and thickness is equally easy to source, so check availability before a size goes on the drawings.
Unequal-leg angle weight chart
Unequal-leg angles list the long leg first. They are common as lintels, where the long leg is usually vertical for stiffness and the short leg carries the brick.
| Metric designation | Imperial (in) | kg/m | lb/ft |
|---|---|---|---|
| L64x51x6.4 | 2-1/2 x 2 x 1/4 | 5.4 | 3.62 |
| L76x51x6.4 | 3 x 2 x 1/4 | 6.1 | 4.1 |
| L76x64x6.4 | 3 x 2-1/2 x 1/4 | 6.7 | 4.5 |
| L89x64x6.4 | 3-1/2 x 2-1/2 x 1/4 | 7.3 | 4.9 |
| L89x76x7.9 | 3-1/2 x 3 x 5/16 | 9.8 | 6.6 |
| L102x76x6.4 | 4 x 3 x 1/4 | 8.6 | 5.8 |
| L102x76x9.5 | 4 x 3 x 3/8 | 12.6 | 8.5 |
| L102x89x6.4 | 4 x 3-1/2 x 1/4 | 9.2 | 6.2 |
| L102x89x7.9 | 4 x 3-1/2 x 5/16 | 11.4 | 7.7 |
| L102x89x9.5 | 4 x 3-1/2 x 3/8 | 13.5 | 9.1 |
| L127x76x7.9 | 5 x 3 x 5/16 | 12.1 | 8.2 |
| L127x89x7.9 | 5 x 3-1/2 x 5/16 | 12.9 | 8.7 |
| L127x89x9.5 | 5 x 3-1/2 x 3/8 | 15.4 | 10.4 |
| L152x89x9.5 | 6 x 3-1/2 x 3/8 | 17.3 | 11.7 |
| L152x102x9.5 | 6 x 4 x 3/8 | 18.2 | 12.3 |
| L152x102x12.7 | 6 x 4 x 1/2 | 24.0 | 16.2 |
| L203x102x12.7 | 8 x 4 x 1/2 | 29.0 | 19.6 |
| L203x152x12.7 | 8 x 6 x 1/2 | 34.1 | 23.0 |
Values from the AISC Shapes Database (version 15.0), rounded.
Thickness moves the weight more than anything else. Going from 1/4 in to 3/8 in on the same 4 x 4 legs adds about half again as much steel. When two people quote different weights for "a 4 inch angle", check the thickness first.
How the formula compares with the published tables
The formula is good enough for estimating and for sizes that are not in your table. Here is how close it lands:
| Angle | Formula (kg/m) | Published (kg/m) |
|---|---|---|
| L51x51x6.4 | 4.8 | 4.7 |
| L76x76x6.4 | 7.3 | 7.3 |
| L102x102x9.5 | 14.5 | 14.6 |
| L127x89x7.9 | 12.9 | 12.9 |
| L152x102x9.5 | 18.2 | 18.2 |
| L152x152x12.7 | 29.0 | 29.2 |
For anything you will invoice, lift or put on a load plan, use the published value from a section table.
Worked examples
A brick lintel over a window. A 1,800 mm opening with 150 mm bearing at each end needs an angle 2.1 m long. If the designer specifies an L102x89x7.9:
- 11.4 kg/m x 2.1 m = 24 kg (about 53 lb)
That is a one-person carry, but awkward at the top of a ladder. Lintel sizing itself comes from the code tables or the designer; see steel lintel sizes under the Ontario Building Code.
A frame for a mechanical unit. A rectangular support frame uses four pieces of L76x76x9.5: two at 2.4 m and two at 1.2 m.
- Total length: 2 x 2.4 + 2 x 1.2 = 7.2 m
- Weight: 7.2 x 10.7 = 77 kg before clips, plates and welds
An order of ledger angles. Twenty pieces of L152x102x9.5 at 3.0 m each:
- 60 m x 18.2 kg/m = 1,092 kg, roughly 1.1 tonnes
At that weight, delivery and handling on site become part of the planning: a tonne of loose angle needs a forklift or a crane truck to unload, not two people.
From a weight chart to an order
The weight of the finished pieces is not always the weight you buy. A few things to keep in mind:
- Stock lengths and drops. Angle is cut from stock lengths, and the leftover pieces may not be usable on your job. How the cuts nest into stock lengths decides how much steel is actually purchased.
- Holes and copes. Holes and notches remove a little steel. For estimating, ignore them; they rarely change a total by more than a fraction of a percent.
- Welded parts. Plates, clips and lugs welded to angles add weight. Count them separately.
- Coatings. Paint adds very little. Galvanizing adds a zinc layer, which matters on large orders; ask the galvanizer if you need a number.
- Grade. Weight is the same for every carbon steel grade. A 350W angle weighs what a 300W angle of the same size weighs. Our article on steel channel grades explains the grades used for channels and angles.
If you are pricing angle, the weight is the starting point, but it is not the whole story. See steel angle prices in Canada for what goes into a quote, and angle vs bent plate if you are choosing between a rolled angle and a formed plate.
Why your number may not match exactly
You may see slightly different weights for the same angle from different sources. Common reasons:
- Rounding. Tables round to one decimal in kg/m or to a tenth of a pound per foot, and converted values pick up small differences.
- Designation conversions. A 4 x 4 x 3/8 in angle is listed as L102x102x9.5 in metric. True metric angles rolled to round millimetre sizes, which you may see on imported steel, have slightly different weights.
- Formula vs table. As shown above, the simple formula ignores the fillet and toe radii.
- Rolling tolerances. Real bars vary slightly from nominal dimensions within the tolerances of the material standard.
None of these matter for a rough estimate. They can matter for a crane pick or a tight shipping weight, so use the published mass and add a reasonable margin.
Angle cut and fabricated to your list
We supply steel angle cut to length and fabricate it into lintels, frames, ledgers and supports, with holes, welded plates and clips to your drawings. Shop welding is CWB certified, and orders are delivered across the GTA and Ontario.
Send us your angle list or drawings for a quote, or see the steel products we supply and fabricate.
Frequently asked questions
How do you calculate the weight of a steel angle?
Multiply the thickness by the sum of the two legs minus the thickness, all in millimetres, then multiply by 0.00785 to get kg per metre. For an L102x102x9.5: 9.5 x (102 + 102 minus 9.5) x 0.00785 = about 14.5 kg/m. Published tables are slightly higher because they include the root fillet.
How much does a 4 x 4 steel angle weigh?
It depends on the thickness. An L102x102x6.4 (4 x 4 x 1/4 in) weighs about 9.8 kg/m (6.6 lb/ft), an L102x102x9.5 (4 x 4 x 3/8 in) about 14.6 kg/m (9.8 lb/ft) and an L102x102x12.7 (4 x 4 x 1/2 in) about 19.0 kg/m (12.8 lb/ft).
How do I convert angle weight from kg/m to lb/ft?
Divide kg/m by 1.488. For example, 14.6 kg/m divided by 1.488 is about 9.8 lb/ft. To go the other way, multiply lb/ft by 1.488.
Why is my calculated angle weight different from the supplier's?
Simple formulas ignore the rounded fillet at the inside corner, tables are rounded, and imperial and metric designations are converted. Differences of a percent or two are normal. Use the published mass from a section table for anything you will lift, ship or invoice.
