Steel Beam Load Tables — W-Shape Allowable Uniform Load (kips)

These load tables give the maximum total uniformly distributed load (UDL) for simply supported W-shape steel beams based on the controlling limit state — either moment capacity or serviceability deflection (L/360 live load limit).

Basis: AISC 360-22, LRFD method, Grade A992 steel (Fy = 50 ksi), unbraced compression flange = 0 (fully braced).

Note: These are ballpark values for preliminary design. Always verify with a qualified engineer for final design. Actual capacity depends on unbraced length, loading pattern, and connection details.

W8 Series — Maximum UDL (kips), Simply Supported, Fully Braced

Section Span 10 ft Span 12 ft Span 14 ft Span 16 ft Span 18 ft Span 20 ft
W8x10 18 13 9.5 7.2 5.7 4.6
W8x18 34 24 17 13 10.5 8.5
W8x31 62 43 31 24 19 15
W8x40 80 56 41 31 24 20

W10 Series — Maximum UDL (kips)

Section Span 12 ft Span 14 ft Span 16 ft Span 18 ft Span 20 ft Span 24 ft
W10x22 34 25 19 15 12 8.3
W10x26 42 31 24 19 15 10
W10x30 50 37 28 22 18 12
W10x45 76 56 43 34 27 19

W12 Series — Maximum UDL (kips)

Section Span 14 ft Span 16 ft Span 18 ft Span 20 ft Span 24 ft Span 28 ft
W12x19 27 21 16 13 9.0 6.5
W12x26 41 31 24 20 14 10
W12x35 57 44 34 28 19 14
W12x50 86 66 52 42 29 21

W14 Series — Maximum UDL (kips)

Section Span 16 ft Span 18 ft Span 20 ft Span 24 ft Span 28 ft Span 32 ft
W14x22 30 23 19 13 9.4 7.2
W14x30 44 35 28 19 14 11
W14x38 57 45 36 25 18 14
W14x48 76 60 48 34 24 18

W16 Series — Maximum UDL (kips)

Section Span 16 ft Span 18 ft Span 20 ft Span 24 ft Span 28 ft Span 32 ft
W16x26 42 33 27 19 14 10
W16x31 52 41 33 23 17 13
W16x40 70 55 44 31 22 17
W16x57 102 80 65 45 33 25

W18 Series — Maximum UDL (kips)

Section Span 18 ft Span 20 ft Span 24 ft Span 28 ft Span 32 ft Span 36 ft
W18x35 53 43 30 22 17 13
W18x46 73 59 41 30 23 18
W18x55 90 73 51 37 28 22
W18x76 130 105 73 54 41 32

W21 Series — Maximum UDL (kips)

Section Span 20 ft Span 24 ft Span 28 ft Span 32 ft Span 36 ft Span 40 ft
W21x44 73 51 37 28 22 18
W21x57 98 68 50 38 30 24
W21x68 120 83 61 47 37 30

W24 Series — Maximum UDL (kips)

Section Span 24 ft Span 28 ft Span 32 ft Span 36 ft Span 40 ft Span 44 ft
W24x55 88 65 49 39 31 26
W24x68 113 83 63 50 40 33
W24x84 143 105 80 63 51 42

W27 Series — Maximum UDL (kips)

Section Span 28 ft Span 32 ft Span 36 ft Span 40 ft Span 44 ft Span 48 ft
W27x84 120 91 72 58 48 40
W27x94 138 105 83 67 55 46
W27x114 171 130 103 83 69 58

W30 Series — Maximum UDL (kips)

Section Span 30 ft Span 36 ft Span 40 ft Span 44 ft Span 48 ft Span 52 ft
W30x90 133 98 79 65 54 46
W30x108 163 120 97 80 67 57
W30x132 202 149 120 99 83 70

LRFD Basis — How the Table Values Are Computed

Each table entry is the lower of two limits:

Moment limit: The beam must satisfy φMn ≥ Mu = w × L² / 8. For fully braced W-shapes, φMn = 0.9 × Fy × Zx (plastic moment). Rearranging: w_max = 8 × φMn / L².

Deflection limit: Live load deflection ≤ L/360. For a UDL: δ = 5wL⁴/384EI. Setting δ = L/360 gives: w_max = 384EI/1800L³ = 0.213EI/L³.

At short spans, the moment limit governs (capacity drops as 1/L²). At long spans, the deflection limit takes over (capacity drops as 1/L³), explaining the steeper fall-off in the longer span columns.

Note on live vs total load: The tables give maximum total factored load for LRFD. For the deflection check, the live load fraction (typically 50–70% of total) governs. If your live load fraction is low, moment will control across more of the span range. Use the beam capacity calculator to separate dead and live load checks.

Effect of Lateral Bracing

These tables assume continuously braced compression flange (Lb = 0). This is valid when:

When the compression flange is unbraced over a length Lb > Lp, the nominal moment capacity Mn is reduced by lateral-torsional buckling per AISC 360-22 Section F2. The reduction depends on the unbraced length relative to Lp and Lr:

For beams with unbraced segments between lateral restraints — such as cantilevers, beams in moment frames without decking, or bottom flange compression in continuous beams — do not use these tables. Use the full beam calculator with the actual unbraced length.

How to Use These Tables

  1. Estimate the total factored load (dead + live, or service load if checking deflection)
  2. Find the span of your beam
  3. Select the lightest W-shape where the table value exceeds your total load
  4. Verify with the full calculator — tables assume fully braced, UDL loading

Preliminary Sizing Rule of Thumb

For typical office floor loading (80 psf total, tributary width 10 ft):

Span Total Load Typical Section
20 ft 16 kips W12x26
24 ft 19 kips W14x30
28 ft 22 kips W16x31
32 ft 26 kips W18x40
36 ft 29 kips W18x46
40 ft 32 kips W21x44

Frequently Asked Questions

How do I read a beam load table? Find the row for your W-shape and the column for your span. The table value is the maximum total uniform load (dead + live factored together for LRFD) the beam can carry without exceeding either the moment capacity (phi × Mn) or the L/360 live load deflection limit — whichever is lower. If your required load is less than the table value, the section works for that span.

Why does the load capacity drop so steeply with span? Moment capacity controls at short spans and equals phi × Mn, which is constant regardless of span. But the maximum load for moment = 8 × phi × Mn / L², so doubling the span cuts moment-based capacity to one quarter. At longer spans, deflection (varying as wL⁴/EI) becomes the governing limit state even earlier. The rapid drop you see in the table reflects this L² to L⁴ sensitivity.

Do these tables account for lateral-torsional buckling? No — the tables assume the compression flange is continuously braced (Lb = 0). If the beam has unbraced segments between lateral restraints (deck attachment, bridging, or framing connections), the plastic moment capacity Mp must be reduced to the lateral-torsional buckling moment Mn per AISC 360 Section F2. Use the full beam calculator for any beam with Lb > Lp.

What W-shape is typically used for a 24-foot office beam? For typical office loading of 80 psf total with a 10-foot tributary width: w = 0.8 kip/ft, W_total = 19.2 kips. From the W14 table, a W14x30 carries 19 kips at 24 ft — right at the limit. Step up to W14x38 (25 kips) for margin, or use W16x31 (23 kips at 24 ft) for a slightly lighter alternative with more depth. Always confirm with the exact calculator before specifying.

When should I use W-shapes versus HSS for beams? W-shapes are more efficient in bending due to their high moment of inertia relative to weight — the flanges are far from the neutral axis. HSS (hollow structural sections) are preferred when biaxial bending, torsion, or architectural exposure requires a closed section. For typical floor beams and roof framing, W-shapes are almost always the economic choice. HSS beams appear in exposed conditions, canopies, and curved framing.

Run This Calculation

→ Beam Capacity Calculator — exact moment, shear, and deflection checks per AISC 360 for any W-shape, accounting for unbraced length and actual loading.

→ Beam Span Screener — quickly screen W-shapes by span and uniform load to identify the lightest adequate section.

→ Composite Beam Calculator — composite W-shape with concrete deck per AISC 360 Chapter I for long-span floor systems.

See Also

Disclaimer (educational use only)

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