Free tool · Steel
Beam Span and Load Checker
Check a steel beam for a span and load in seconds: bending, shear and deflection for UK universal beams and columns, with a plain-English result.
Quick answer
Choose a UB or UC size and grade, enter the span and the unfactored loads, and say whether the top flange is held in place. The Koyda checker works out the design bending moment and shear (1.35 × permanent + 1.5 × imposed, self-weight included), compares them with the section's resistance to BS EN 1993-1-1 and the UK National Annex, checks deflection under imposed load against span/360, and shows each as a percentage of capacity. Guidance only: Building Regulations need an engineer's calculations.
Cite this: Koyda Ltd, “Beam Span and Load Checker”, https://www.koyda.com/beam-span-checker/, reviewed 10 October 2026.
Beam checker
Guidance only. Assumes full lateral restraint unless you say otherwise. Not a substitute for a structural engineer: Building Regulations need calculations. What is not checked
Enter a load
Pick a section, enter the span and the loads to see the result.
Show the working
Send your drawings or the engineer's design and Koyda will price the steel, fabrication and installation.
Use the tables and calculator offline
Install the Koyda app: section tables, weight calculator, CSV and PDF downloads, even without signal on site.
How it works
What the checker does
- Design load = 1.35 × permanent (including the beam's weight) + 1.5 × imposed (BS EN 1990 Eq. 6.10, UK NA). Moment wL²/8 + PL/4, shear wL/2 + P/2.
- Bending: plastic resistance Wpl·fy (elastic for Class 3), γM0 = 1.0. Yield strength drops for thick flanges (BS EN 10025-2), e.g. 265 N/mm² for S275 over 16 mm.
- Unrestrained beams: lateral torsional buckling to clause 6.3.2.3 with the UK NA, Mcr from the SN003 formula with C1 1.127 (UDL) or 1.348 (point load), and the load on the top flange when destabilising (more cautious).
- Shear: Vpl,Rd = Av·fy/√3, with the bending resistance reduced at midspan if a point load causes high shear.
- Deflection: imposed load only, against span/360 by default (UK NA NA.2.23). Total deflection is shown for information.
- Result: under 90% pass, 90–100% close (get it checked), over 100% fail.
Checked against SCI worked examples and every bending resistance in the Blue Book load tables (over 36,000 values, all within 1%).
Limits
What it does not check
- Bearings, padstones and the wall, pier or column under each end.
- Connections, end plates, cleats and bolts.
- Web bearing and buckling under point loads or at supports.
- Continuous, cantilever or fixed-end beams; loads off-centre; two-way or torsional loads.
- Fire protection, vibration, corrosion and temporary works.
- Channels (PFC) and Class 4 sections.
Not a design
Guidance only. This checks one simply supported steel beam for the loads you enter. It assumes the top flange is fully restrained unless you choose otherwise. It does not check connections, bearings, padstones, the walls or columns below, web bearing, fire, vibration or torsion, and it is not a substitute for a structural engineer. Building Regulations approval needs calculations from a competent engineer.
Questions
Frequently asked questions
Can I use this instead of an engineer?
No. It is a quick check to see whether a size is in the right range before you ask for a design. Building control will want calculations from a competent structural engineer that cover the beam, its bearings and padstones, the connections and the structure below.
What does 'restrained' mean?
A beam is laterally restrained when something fixed to the top (compression) flange stops it moving sideways and twisting, for example floor joists on hangers, a concrete slab or a fixed deck along the length. If nothing holds the top flange between the supports, choose unrestrained: the beam can buckle sideways (lateral torsional buckling) at a much lower load.
Which loads should I enter?
Unfactored (characteristic) loads in kN per metre run along the beam, split into permanent loads (the weight of floors, walls, roofs and finishes) and imposed loads (people and furniture, storage, roof maintenance). The checker adds the beam's own weight and applies the Eurocode factors 1.35 and 1.5. Use the floor-area helper to turn kN/m² into kN/m.
Why is deflection checked with imposed load only?
The UK National Annex to BS EN 1993-1-1 (NA.2.23) gives span/360 for beams carrying plaster or other brittle finishes, and span/200 for other beams, both under variable (imposed) load. Total deflection under all loads is shown for information.
Why no channels (PFC)?
A channel twists unless the load passes through its shear centre, which sits outside the web. That needs a check this tool does not do, so channels are left out. Ask an engineer, or use a UB.
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Next steps
- Universal beam sizes and properties
- Steel weight calculator
- Steel Quote Builder: weights, cutting list and quote
- Paint and galvanising area calculator
- Lintel and padstone helper: a beam over an opening, with end reactions
- All guides and tools
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