Steel Weight Calculator

Calculate structural steel mass—often called steel weight in schedules—from section tables, length, and quantity. Pick a common section to fill the unit mass automatically, or enter a custom value for plates and built-up members.

Steel Weight Calculator

Section lookupUnit Mass (kg/m)Length (m)Qtykg

How It Works

Every structural steel section has a published unit mass—the mass per unit length. This value accounts for the full cross-section including flanges, web, and fillet radii. Total mass is:

Mass = Unit Mass × Length × Quantity

Unit mass is found in manufacturer section tables and design handbooks. For example, a 610 UB 125 has a unit mass of 125 kg/m, meaning each metre has a nominal mass of 125 kg. The same mass is approximately 84.0 lb/ft; that unit conversion does not turn it into a W24×84.

Common Section Weights

Nominal examples are grouped by their metric or US designation system. Each row represents one physical section; the second mass column is a unit conversion of that same section, not a claimed equivalent from another catalogue. Confirm the current supplier table before procurement or design.

Metric Universal Beams

Sectionkg/mlb/ft
150 UB 14149.41
200 UB 2525.417.07
250 UB 3737.325.06
310 UB 4646.231.04
360 UB 5756.738.1
410 UB 6059.740.12
460 UB 8282.155.17
530 UB 9292.462.09
610 UB 12512584
760 UB 197197132.38

US Universal Beams

Sectionkg/mlb/ft
W6×913.399
W8×1725.317
W10×2638.6926
W12×3044.6430
W14×3856.5538
W16×4059.5340
W18×5581.8555
W21×6292.2762
W24×84125.0184
W30×132196.44132

Metric Universal Columns

Sectionkg/mlb/ft
100 UC 1514.89.95
150 UC 303020.16
200 UC 4646.231.04
250 UC 7372.948.99
310 UC 9796.865.05
310 UC 158158106.17

US Universal Columns

Sectionkg/mlb/ft
W4×1319.3513
W6×2029.7620
W8×3146.1331
W10×4972.9249
W12×6596.7365
W12×106157.75106

Metric Channels

Sectionkg/mlb/ft
100 PFC8.335.6
150 PFC17.711.89
200 PFC22.915.39
250 PFC35.523.85
300 PFC40.126.95
380 PFC55.237.09

US Channels

Sectionkg/mlb/ft
C4×5.48.045.4
C6×10.515.6310.5
C8×11.517.1111.5
C10×2029.7620
C12×20.730.820.7
C15×33.950.4533.9

Metric Equal Angles

Sectionkg/mlb/ft
50×50×53.772.53
65×65×65.873.94
75×75×89.026.06
100×100×1014.29.54
150×150×1227.918.75

US Equal Angles

Sectionkg/mlb/ft
L2×2×¼4.753.19
L2½×2½×⁵⁄₁₆7.445
L3×3×⅜10.717.2
L4×4×½19.0512.8
L6×6×½29.1719.6

Metric Hollow Sections

Sectionkg/mlb/ft
SHS 50×50×34.252.86
SHS 75×75×510.36.92
SHS 100×100×617.511.76
RHS 200×100×626.417.74
CHS 114.3×6.01610.75
CHS 168.3×6.02416.13
CHS 219.1×8.041.627.95

US Hollow Sections

Sectionkg/mlb/ft
HSS2×2×⅛4.242.85
HSS3×3׳⁄₁₆10.276.9
HSS4×4×¼18.1612.2
HSS8×4×¼27.3818.4
HSS4.5×0.23716.0710.8
HSS6.625×0.2524.4116.4
HSS8.625×0.32242.5628.6

Unit Mass vs Calculated Mass

Published unit masses are based on nominal section geometry and the density basis used by the relevant catalogue. Delivered mass can vary within the product standard's permitted dimensional and mass tolerances. Use the project's nominated supplier data and procurement allowances rather than assuming one universal tolerance.

Calculating from Dimensions

If you don't have a published unit mass - for example, for a steel plate or a non-standard built-up section - you can calculate it from cross-sectional area:

Unit Mass (kg/m) = Area (mm²) × 7850 (kg/m³) × 10⁻⁶

For a simple rectangular plate:

Unit Mass (kg/m) = Width (mm) × Thickness (mm) × 0.00785

For example, a 200 mm × 10 mm flat plate weighs 200 × 10 × 0.00785 = 15.7 kg/m.

Material Take-Off Tips

  • Apply a project-specific allowance for connections, stiffeners, laps, and waste
  • Include gusset plates, base plates, cleats, bolts, and weld metal where material take-off scope requires them
  • Confirm available stock lengths and cutting plans with the fabricator before rounding quantities
  • Obtain coating and fire-protection mass allowances from the specified system supplier

Disclaimer

This calculator provides estimates based on nominal section data. For procurement, always confirm unit masses with your steel supplier or fabricator. Delivered mass may vary due to rolling tolerances and cut lengths. Apply your own professional judgement.

Related Calculators

Need to Analyse a Structure?

Model beams, frames, plates, and trusses in 3D with our free structural analysis tool. No download. No signup. Just open and start modelling.