This free steel beam weight calculator turns a section choice and a length into the total weight in kilograms. Choose a standard Indian ISMB (I-beam) or ISMC (channel) section, enter the length in metres and the number of pieces, and read the weight per metre, weight per piece and total weight instantly — using the published IS 808 nominal weights. No sign-up, results update as you type.
How to calculate steel beam weight
Standard rolled sections have a fixed published weight per metre, so the weight calculation is simple multiplication:
Total weight = weight per metre × length × quantity
- Weight per metre — the IS 808 nominal value for the chosen section (kg/m). The dropdown above carries this figure for every ISMB and ISMC size.
- Length — the length of one beam in metres.
- Quantity — how many identical pieces you are ordering or issuing.
Because the weight per metre is already known for standard sections, you never need the steel density or the cross-section area — just pick the section and enter the length.
Worked example — ISMB 200
Take an ISMB 200 beam, which weighs 25.4 kg/m:
- Weight per metre = 25.4 kg/m
- Weight per piece = 25.4 × 6 m = 152.4 kg
- For 10 pieces: 152.4 × 10 = 1,524 kg total
So a lot of ten 6-metre ISMB 200 beams weighs about 1.52 tonnes — useful for a transport quote, a crane lift plan or a stores issue note.
ISMB & ISMC standard weights
These are the nominal weights per metre (IS 808) used by this calculator. ISMB are medium-weight I-beams; ISMC are medium-weight channels.
| Section | Type | Weight (kg/m) |
|---|---|---|
| ISMB 100 | I-Beam | 11.5 |
| ISMB 125 | I-Beam | 13.0 |
| ISMB 150 | I-Beam | 15.0 |
| ISMB 175 | I-Beam | 19.3 |
| ISMB 200 | I-Beam | 25.4 |
| ISMB 250 | I-Beam | 37.3 |
| ISMB 300 | I-Beam | 44.2 |
| ISMB 350 | I-Beam | 52.4 |
| ISMB 400 | I-Beam | 61.6 |
| ISMB 450 | I-Beam | 72.4 |
| ISMB 500 | I-Beam | 86.9 |
| ISMB 600 | I-Beam | 122.6 |
| ISMC 75 | Channel | 7.14 |
| ISMC 100 | Channel | 9.56 |
| ISMC 125 | Channel | 13.1 |
| ISMC 150 | Channel | 16.4 |
| ISMC 200 | Channel | 22.1 |
| ISMC 250 | Channel | 30.4 |
| ISMC 300 | Channel | 35.8 |
| ISMC 400 | Channel | 49.4 |
ISMB is an I-section used mainly where bending and column loads dominate; ISMC is a C-section used for purlins, framing, bracing and built-up members. For the same depth, the channel is lighter and less stiff in bending.
Standard vs built-up beam weight
The figures above only apply to standard rolled sections. As soon as you move to a fabricated beam, the weight per metre changes:
- Standard rolled beam — ISMB / ISMC with a published kg/m. Weight is just kg/m × length, which is exactly what this tool does.
- Plate girder / built-up beam — made from welded plates. There is no standard kg/m, so weight must be computed from each plate’s cross-section:
area × length × 7,850 kg/m³, summed for the flanges and web, plus stiffeners. - Castellated / cellular beams — lighter than the parent section because material is removed for the openings; never use the parent kg/m directly.
Always confirm the section is a standard rolled profile before trusting a per-metre weight. For fabricated members, weigh the plate parts individually.
From weight maths to live procurement in OEMup
A calculator answers one beam. Running a fabrication shop means tracking every section, every offcut and every job cost — and the spreadsheet version drifts the moment someone forgets to log an issue. Inside OEMup ERP, steel sections are stored with their weights, so material issues, offcuts, job costing and customer quotes calculate beam and plate weights automatically — no re-keying kg/m by hand. Start free or explore the full inventory & costing features to see steel handled end to end.
Beam Weight Calculator — frequently asked questions
How do you calculate the weight of a steel beam?
Multiply the section’s standard weight per metre (kg/m) by the length in metres, then by the quantity: Total weight = weight per metre × length × quantity. For example an ISMB 200 weighs 25.4 kg/m, so a 6 m beam weighs 25.4 × 6 = 152.4 kg, and 10 such beams weigh 1,524 kg.
What is the weight per metre of an ISMB 200 beam?
An ISMB 200 weighs about 25.4 kg per metre per IS 808, so a 6 m length is roughly 152.4 kg. Actual rolled weight can vary a few per cent by mill and tolerance class, but 25.4 kg/m is the standard figure used for estimating and procurement.
What is the difference between ISMB and ISMC?
ISMB is an Indian Standard Medium Weight Beam — an I-section with two flanges and a central web, used for beams and columns. ISMC is an Indian Standard Medium Weight Channel — a C-section used for purlins, frames and built-up members. For the same depth, an ISMC is lighter and less stiff in bending than an ISMB.
Why does actual beam weight differ from the standard?
The IS 808 kg/m values are nominal, based on the ideal cross-section and 7,850 kg/m³ steel density. Real sections vary within rolling tolerances, so actual weight can be a few per cent above or below nominal. Cuts, copes, holes and coatings also change delivered weight, and built-up beams have no standard kg/m at all.
Need another shop-floor tool? Try our free Metal Weight Calculator or browse the full calculator library.
Stop costing steel in spreadsheets
OEMup stores every section with its weight — beam and plate weights, offcuts, material issues and quotes calculated for you. Built for Indian fabrication and manufacturing SMEs.
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