Instantly calculate ISMB beam weight by section and length as per IS 808:1989. Includes full weight chart for ISMB 100 to ISMB 600, sectional dimensions, flange & web thickness, Ixx, Iyy and cost estimation — India 2026.
Select ISMB section, enter length and quantity — get total weight, cost estimate and section properties instantly
Complete ISMB weight per metre, dimensions and section properties for ISMB 100 to ISMB 600 — click any row to load into calculator
| Section | Depth D (mm) | Flange Width B (mm) | Web Thk tw (mm) | Flange Thk tf (mm) | Area A (cm²) | Ixx (cm⁴) | Iyy (cm⁴) | Weight (kg/m) | Weight/12m (kg) |
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Click any row to auto-fill the calculator above with that section.
* All values as per IS 808:1989 (Reaffirmed 2021). Weight per metre = Area (cm²) × 0.7850 kg/cm²/m. Ixx = Moment of inertia about major axis; Iyy = Moment of inertia about minor axis. Standard supply length in India = 12 metres (cut lengths also available). Source: IS 808:2021 — BIS.
How the ISMB beam weight per metre is derived from IS 808 section properties
Method 1 — Using IS 808 Tabulated Weight (Simplest & Most Accurate)
Method 2 — From Cross-Sectional Area (Theoretical)
Method 3 — Approximate from Flanges + Web Geometry
ISMB designation = depth in mm. ISMB 300 = 300mm deep beam. Select from IS 808 table or use the calculator above. The designation tells you the nominal depth — actual depth matches exactly.
Read weight per metre from IS 808 weight chart above. For ISMB 250 = 37.3 kg/m. This value includes all material (flanges + web + fillets) at standard MS density (7850 kg/m³).
Total weight per piece = Weight per metre × Length (m). For ISMB 250 at 6m: 37.3 × 6 = 223.8 kg per piece. This is your basis for transport, hanger load, and procurement weight.
Total order weight = Weight per piece × Number of pieces. For 15 pieces of ISMB 250 at 6m: 223.8 × 15 = 3357 kg = 3.357 tonnes. Convert to tonnes for pricing at per-tonne market rate.
Understanding where ISMB fits among the Indian Standard beam families — choose the right section for your application
Where ISMB beams are specified and used across Indian construction and industrial projects
ISMB beams form the horizontal frame members in steel-framed buildings across India. ISMB 200–400 are the most common sizes for floor beams in commercial buildings, industrial sheds, and warehouses up to 5 storeys.
Pre-engineered buildings (PEB) and conventional steel structures use ISMB extensively for crane girders, runway beams, portal frame rafters and purlin support beams. ISMB 450–600 are common for heavy crane runway beams in Indian factories.
Smaller road bridges and pedestrian walkways in India use ISMB plate girder composites. ISMB 600 with welded cover plates is a common section in small to medium span bridge construction for state highway and rural road projects.
Pipe racks, equipment platforms, mezzanine floors and staircases in Indian process plants (refineries, chemical plants, power stations) use ISMB 200–400 for framing. IS 800:2007 governs the design using IS 808 section properties.
ISMB 100–200 are widely used as soldier beams and waling sections in deep excavation shoring systems across Indian construction sites. They are also used as primary beams in steel formwork systems for concrete slabs.
Indian metro rail viaducts and station structures use large ISMB sections (ISMB 500–600) for platform canopies, maintenance access frames, and electrical equipment support structures. SAIL and JSPL supply certified IS 808 beams for rail projects.
Material grades, supply lengths, tolerances and 2026 procurement references for ISMB beams in India
Practical advice for structural engineers, site engineers and procurement teams
Do not attempt to calculate ISMB weight from dimensions alone — the actual weight is higher than the simple flange+web approximation due to fillet radii at the web-flange junction. The IS 808 tabulated kg/m values already include fillets and are the correct reference for all procurement and structural purposes.
Add 2–3% extra weight to your calculated order quantity to account for mill tolerance (±2.5%) and minor cutting waste. For beam-heavy projects, also add 0.5–1% for end-squaring cuts. This prevents short deliveries that stall fabrication and require emergency premium-rate purchases.
Always negotiate ISMB price on a per-tonne basis. Convert your piece count to total tonnes using the IS 808 weight calculator above, then request per-tonne pricing from stockists. A ₹1,000/tonne reduction on a 50-tonne ISMB order saves ₹50,000 — significant on competitive projects.
(1) Weigh a sample piece and compare against IS 808 weight per metre × length (±2.5% tolerance). (2) Measure depth D with a steel tape — must match IS 808 nominal within ±2.5%. (3) Check the MTC (Mill Test Certificate) for IS 2062 grade, heat number, and IS 808 reference. All three checks take under 10 minutes and prevent wrong-material acceptance.
ISMB 200 (24.2 kg/m) can sometimes substitute ISLB 250 (20.7 kg/m) + extra plate in value-engineering exercises. Before substituting, verify Ixx and Zxx (section modulus) are adequate — never substitute based on weight alone. Use IS 800:2007 beam design checks for any section substitution.
For painting or shot-blasting cost estimation, the surface area per metre of ISMB ≈ perimeter of cross-section. Approximate formula: Surface area (m²/m) ≈ (2B + 2D − 2tw) / 1000, where B = flange width, D = depth, tw = web thickness (all in mm). For ISMB 300: (2×140 + 2×300 − 2×7.7) / 1000 ≈ 0.865 m²/m for blast & paint costing.
More IS 808 and structural steel weight tools for Indian projects
Common questions from structural engineers, contractors and procurement teams in India