This free angle weight calculator turns the dimensions of a steel L-section into its weight — for both equal and unequal MS angles. Enter leg A, leg B, thickness, length and quantity, and read the weight per metre, weight per piece and total weight instantly, with the cross-section area shown alongside. Change the density to weigh stainless, aluminium or brass angles too. No sign-up, results update as you type.
How to calculate angle (L-section) weight
An angle is an L-shaped section. Its weight comes from two simple steps — find the cross-section area, then turn that area into a weight using the material density:
Area (mm²) = (Leg A + Leg B − thickness) × thickness
Weight per metre (kg/m) = Area × 0.000001 × density
- Area — the two legs share the corner once, so the thickness is subtracted once to avoid double-counting it:
(A + B − t) × t. - Weight per metre — convert area from mm² to m² (multiply by 1e−6), then multiply by density in kg/m³ (7850 for mild steel).
- Weight per piece =
weight per metre × length (m). - Total weight =
weight per piece × quantity.
Worked example — ISA 50×50×6
Take a standard equal angle ISA 50×50×6, supplied in a 6 metre length, in mild steel (density 7850 kg/m³):
- Area = (50 + 50 − 6) × 6 = 564 mm²
- Weight per metre = 564 × 0.000001 × 7850 = 4.43 kg/m
- Weight per piece = 4.43 × 6 = 26.55 kg
- For 10 pieces, total = 26.55 × 10 = 265.5 kg
The IS handbook nominal weight for ISA 50×50×6 is about 4.5 kg/m — the tiny difference is the root-radius material the simple formula ignores, so our estimate sits within ~1–2%.
Equal vs unequal angles
The same formula handles both shapes — only the leg values change:
- Equal angle (e.g. 50×50×6) — both legs are the same length and the section is symmetric about its corner. In the calculator, set leg A and leg B to the same value.
- Unequal angle (e.g. 75×50×6) — the legs differ in length, making the section stiffer about one axis. Enter the long leg as A and the short leg as B (the order does not change the weight).
Because the area formula is symmetric in A and B, swapping the two legs gives the same weight — so you never have to worry about which leg is which.
Density of common metals
Angles are rolled in several metals. Change the density input to weigh a non-steel angle:
| Metal | Density (kg/m³) | Notes |
|---|---|---|
| Mild steel | 7850 | The default — standard MS / IS angles. |
| Stainless steel | 8000 | Slightly denser than mild steel; common grades 304 / 316. |
| Aluminium | 2700 | About one-third the weight of steel for the same section. |
| Brass | 8500 | Heavier than steel; decorative and architectural angles. |
Densities vary slightly by alloy and grade — use your mill or supplier figure where exact weight matters.
From weight maths to live procurement in OEMup
A calculator answers one section. Running a fabrication shop means weighing dozens of angles, plates and bars across every cutting list, BOM and purchase order — and a spreadsheet drifts the moment a section size changes. Inside OEMup ERP, section weights are built in: angle, plate, channel and bar weights flow straight into cutting lists, bills of materials, stock valuation and supplier RFQs, so material weight is consistent from quote to GST invoice — no re-keying. Start free or explore the full inventory & production features to see material weights handled end to end.
Angle Weight Calculator — frequently asked questions
How do you calculate the weight of an angle?
Cross-section area = (leg A + leg B − thickness) × thickness in mm². Multiply by 0.000001 for m², then by density (7850 kg/m³ for mild steel) to get weight per metre, then by length and quantity. An ISA 50×50×6 gives 564 mm², 4.43 kg/m, and 26.55 kg for a 6 m bar.
What is the formula for MS angle weight per metre?
Weight per metre (kg/m) = (leg A + leg B − thickness) × thickness × density × 0.000001, with legs and thickness in mm and density in kg/m³. Use 7850 for mild steel. Example: a 50×50×6 MS angle = (50+50−6) × 6 × 7850 × 0.000001 = 4.43 kg/m.
What is the difference between equal and unequal angles?
An equal angle has both legs the same length (e.g. 50×50) and is symmetric about its corner; an unequal angle has legs of different lengths (e.g. 75×50), which makes it stiffer about one axis. The weight formula is identical for both — to weigh an equal angle, just enter the same value for leg A and leg B.
How accurate is the angle weight formula?
The (A + B − t) × t formula is accurate to within about 1–2% for standard rolled angles. Real IS and ISA angles add a fillet radius and rounded toes the formula ignores, so catalogue weights run marginally higher. It is accurate enough for estimating and cutting lists; use IS handbook nominal weights for billing.
Need another material tool? Try our Metal Weight Calculator or browse the full calculator library.
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