Equal Angle Weight Calculator
Mass per metre and total for equal angle steel.
Quick answer
With the default inputs: Leg length 50 · Thickness 5 · Length each 6 etc.Total mass 223.72 kg
Edit the inputs below to recalculate.Inputs
Result
Total mass
223.72kg
| Mass per metre | 3.729kg/m |
| Mass each | 22.372kg |
| Total length | 60.00m |
| Section area | 475.00mm² |
| In tonnes | 0.2237t |
| Length per tonne | 268.2m/t |
| Surface area | 12.00m² |
| Radius of gyration (approx.) | 10.0mm |
The (2a − t) × t × 0.00785 form unfolds the angle into a flat 2a − t wide and ignores the root radius, so it runs 1-3% light against table values. Use published tables for exact figures; this is for quick estimating.
Reverse: known result, work out one input
Enter a target result; the other inputs stay fixed and this one is worked out.
Formula
| Mass per metre | W = (2a − t) × t × 0.00785 |
| Developed width | b = 2a − t |
| Section area | A = (2a − t) × t |
| Total | per metre × length × quantity |
| Unequal angle | W = (a + b − t) × t × 0.00785 |
| Surface area | ≈ 4a × length |
∠50 × 5, 6 m each, ten lengths: 3.729 kg/m, 22.37 kg each, 223.73 kg in total, a 475 mm² section and about 268 m per tonne.
How to work it out
- Unit weight: W = (2a − t) × t × 0.00785 with side a and thickness t in mm. The expression unfolds both legs into a rectangle and removes the one t × t of overlap.
- For 50 × 5: (100 − 5) × 5 × 0.00785 = 3.73 kg/m. The standard table gives 3.77; the difference is the root radius.
- Multiply by length and count for the total.
- Unequal angles use (a + b − t) × t × 0.00785 with both legs.
- For accurate settlement use the mill table; the formula runs about 1% light.
Where it goes wrong
- Adding the two legs separately — 2 × a × t × 0.00785 double-counts the corner and gives 3.93 for a 50 × 5, 5% high.
- Using the bounding rectangle — a × a × 0.00785 is the square bar formula and roughly doubles the weight of an angle.
- Ignoring the root radius — the formula sits about 1% below the table, which is 100 t on every 10000 t purchased.
- Applying the equal-angle formula to unequal angles — use (a + b − t) when the legs differ.
Material and cost
Q235 angle 4100-4800 CNY/t, Q355 4400-5200, hot-dip galvanised 5000-6000.
On site
- Leg thickness is t; drawings write ∠50×5 for an equal angle 50 mm by 5 mm.
- Single-angle struts are loaded eccentrically; allow a reduction factor around 0.85-0.9 in capacity.
- Minus thickness tolerance of 0.3-0.5 mm is common in the market — check with a caliper on receipt.
Basis
- GB/T 706-2016 Hot-rolled section steel
- GB/T 9787-1988 Hot-rolled equal-leg angle steel — dimensions, shape, mass and tolerances
- GB 50017-2017 Standard for design of steel structures
FAQ
Should an angle purlin stand on edge?
One leg must be vertical — opening down or to the side, never opening up and flat. ∠50×5 has about 3.1 cm³ of section modulus on edge against 1.3 cm³ opening up, a 2.4 times difference. Angles are also singly symmetric and buckle about the weak axis in compression, so braced or boxed sections are needed for struts.
Angle or hollow section for brackets?
Hollow sections resist torsion and compression better, with 20-40% more radius of gyration for the same area, so they buckle less; angles are cheaper, easier to cut and drill, and simpler to connect. Use angles for light bending-dominated work such as pipe supports and cable trays, and hollow sections for slender compression members such as columns and truss struts.
Why do table weights differ from the calculated value?
Because the formula ignores the root radius and toe radii, so the true section is slightly larger than the unfolded rectangle. ∠50 × 5 computes as 3.729 kg/m against 3.77 in the tables, 1.1% apart. The error shrinks as sections get larger and thicker. Above 20 t, use table values — 1% is 200 kg.
Cite this page
Use this format in reports, method statements or coursework. The link is permanent.
Building Calculator. Equal Angle Weight Calculator. 2026-10-25. https://jianzhujisuan.com/en/steel-angle-weight
Results are estimating aids only and are not a design basis. Construction and final accounts must follow the drawings, the applicable standards and an approved method statement. Anything affecting structural safety, shoring or falsework must be checked by a suitably qualified engineer.