Beam Size Chart 2026 – Dimensions, Spans & Load Guide
Beam Size Chart
Dimensions, Spans & Load Guide
Complete beam reference for contractors and builders — standard sizes, spans, load capacities, materials, and application guidance for steel, concrete, and wood beams.
Reviewed by Muhammad Ramzan Babar, PhD Researcher (Plasma Physics) & Calculator Developer — View Profile
Important: Planning Reference Only
All sizes, spans, and load figures on this page are general planning references based on common industry practice. Actual beam selection must account for site-specific loads, material grade, support conditions, and local building codes — always confirm with a licensed structural engineer before construction.
⭐ Master Beam Size Chart
Complete overview showing standard beam sizes, spans, materials, and applications across residential, commercial, and structural construction.
How to Read This Chart
Beam sizing depends on span, load, material, and support conditions working together — no single dimension tells the whole story. Once you have a candidate size, verify it with our Beam Size Calculator or Concrete Beam Calculator.
| Beam Type | Common Sizes | Typical Span Range | Common Applications |
|---|---|---|---|
| Reinforced Concrete | 9″×12″ to 15″×24″ | 10–25 ft | Residential and commercial floors, foundations |
| Steel W-Shape | W6x9 to W18x50 | 10–30 ft | Commercial floors, garages, long spans |
| Steel S-Shape | S6 to S24 | 10–25 ft | Legacy structural, industrial framing |
| LVL Beam | 7¼” to 16″ depth | 8–24 ft | Residential floors, garage headers |
| Glulam Beam | 3⅛”–6¾” width, 9″–24″ depth | 10–30 ft | Exposed beams, vaulted ceilings, commercial |
| Solid/Built-Up Wood | Double 2×8 to Triple 2×12 | 6–14 ft | Residential floors, decks, porches |
⭐ Beam Size by Material
Comparing beam types and common sizes across the primary structural material categories.
| Beam Type | Common Sizes | Typical Applications |
|---|---|---|
| Reinforced Concrete Beams | 9″×12″ to 18″×24″ | Floors, foundations, structural frames |
| Steel I-Beams (S-Shapes) | S3 to S24 | Legacy industrial and structural framing |
| Wide Flange (W) Beams | W4x13 to W44x335 | Commercial and residential structural framing |
| H-Beams | HP8 to HP14 (bearing piles), wide W-shapes | Heavy structural columns, foundations, piles |
| S-Beams | S6 to S20 | Older structures, some industrial applications |
| LVL Beams | 1¾” to 7″ width, 7¼” to 24″ depth | Residential floors, headers, garage openings |
| Glulam Beams | 3⅛” to 8¾” width, 9″ to 30″+ depth | Exposed structural beams, long spans |
| Solid Timber Beams | 4×6 to 8×12 (nominal) | Traditional framing, exposed beams |
| Engineered Wood Beams (I-Joists) | 9¼” to 16″ depth | Floor and roof framing systems |
⭐ Beam Size by Construction Application
Matching beam type and size to common project categories.
| Project | Recommended Beam Type | Typical Beam Size |
|---|---|---|
| Residential Floors | LVL or built-up wood | Double 2×10 to 11⅞” LVL |
| Roof Beams | Glulam or LVL | 3⅛”×9″ to 5⅛”×15″ |
| Garage Openings | Steel W-shape or LVL | W8x18 or 11⅞”–14″ LVL |
| Decks | Pressure-treated wood | Double/Triple 2×10–2×12 |
| Patios | Wood or steel | Double 2×8–2×10 |
| Porches | Wood or LVL | Double 2×8–2×10 |
| Basements | Steel W-shape or reinforced concrete | W8x18–W10x22 or 9″×12″ RC |
| Commercial Buildings | Steel W-shape | W10x22 to W18x50 |
| Warehouses | Steel W-shape or glulam | W12x26 to W24x68 |
| Industrial Structures | Steel W-shape or H-shape | W14x30 and larger |
Reinforced Concrete Beam Size Chart
Common residential reinforced concrete beam sizes by span and typical reinforcement.
| Beam Width | Beam Depth | Typical Span | Typical Reinforcement |
|---|---|---|---|
| 9 in (230 mm) | 12 in (300 mm) | 10–12 ft | 4 bars, 12mm–16mm |
| 9 in (230 mm) | 15 in (375 mm) | 12–15 ft | 4–6 bars, 12mm–16mm |
| 12 in (300 mm) | 18 in (450 mm) | 15–20 ft | 6 bars, 16mm–20mm |
| 12 in (300 mm) | 24 in (600 mm) | 20–25 ft | 6–8 bars, 20mm–25mm |
A common rule of thumb estimates concrete beam depth as span divided by 12 to 15; verify reinforcement with our Rebar Size Chart and Rebar Grade Chart.
⭐ Steel I-Beam Size Chart
Standard AISC steel shapes with depth, width, and weight per foot for common construction sizes.
| Designation | Shape | Depth | Flange Width | Weight per Foot |
|---|---|---|---|---|
| W6x9 | W Shape | 5.90 in | 3.94 in | 9 lb/ft |
| W8x18 | W Shape | 8.14 in | 5.25 in | 18 lb/ft |
| W10x22 | W Shape | 10.17 in | 5.75 in | 22 lb/ft |
| W12x26 | W Shape | 12.22 in | 6.49 in | 26 lb/ft |
| W14x30 | W Shape | 13.84 in | 6.73 in | 30 lb/ft |
| W18x50 | W Shape | 17.99 in | 7.50 in | 50 lb/ft |
| S6x12.5 | S Shape | 6.00 in | 3.33 in | 12.5 lb/ft |
| S12x31.8 | S Shape | 12.00 in | 5.08 in | 31.8 lb/ft |
| HP10x42 | HP Shape (bearing pile) | 9.70 in | 10.08 in | 42 lb/ft |
Reading a Steel Designation
In “W8x18,” the W identifies the shape family (wide flange), the 8 is the approximate nominal depth in inches, and the 18 is the weight per linear foot in pounds — not a fixed physical dimension.
H-Beam vs I-Beam Comparison
Two of the most searched structural steel terms — understanding the practical differences.
| Factor | H-Beam (Wide Flange/W) | I-Beam (S-Shape) |
|---|---|---|
| Shape | Wide, parallel flanges | Narrower, tapered flanges |
| Dimensions | Flange width often close to depth | Flange width notably less than depth |
| Strength | Higher strength-to-weight, resists bending and lateral loads well | Good bending resistance, weaker under lateral/torsional load |
| Applications | Columns, beams, general structural framing | Legacy structural framing, some industrial uses |
| Advantages | Versatile, widely available, efficient material use | Simple shape, historically common |
| Limitations | Can be heavier for equivalent depth in some cases | Largely superseded by W-shapes in modern construction |
LVL Beam Size Chart
Common LVL (Laminated Veneer Lumber) depths and typical residential spans.
| LVL Depth | Typical Span (planning reference) | Residential Applications |
|---|---|---|
| 7¼” | Up to 10 ft | Short headers, small openings |
| 9¼” | 10–14 ft | Floor beams, medium headers |
| 11⅞” | 14–18 ft | Garage headers, floor beams |
| 14″ | 18–22 ft | Long floor spans, larger openings |
| 16″ | 20–24 ft | Extended spans, great room floors |
Glulam Beam Size Chart
Common glued laminated timber sizes for exposed and long-span structural applications.
| Width | Depth | Common Span (planning reference) | Typical Uses |
|---|---|---|---|
| 3⅛” | 9″–12″ | 10–16 ft | Residential roof beams |
| 5⅛” | 12″–18″ | 16–24 ft | Vaulted ceilings, exposed beams |
| 6¾” | 18″–24″ | 24–30 ft | Commercial and heavy residential spans |
| 8¾” | 24″–30″+ | 30 ft+ | Large commercial and industrial structures |
Wood Beam Size Chart
Common built-up and solid timber beam configurations for residential use.
| Configuration | Typical Span (planning reference) | Common Residential Uses |
|---|---|---|
| Double 2×8 | Up to 8 ft | Short floor spans, porches |
| Double 2×10 | 8–10 ft | Standard floor beams, decks |
| Double 2×12 | 10–12 ft | Longer floor spans, larger decks |
| Triple Members (2×10/2×12) | 12–14 ft | Heavier loads, wider spacing |
| Solid Timber (6×10, 8×12) | 10–16 ft | Traditional framing, exposed beams |
⭐ Beam Size by Span
General planning reference matching clear span to typical beam size across materials.
Planning Reference Only
Actual beam selection depends on design loads, material properties, support conditions, applicable building codes, and engineering calculations. This table is a general starting point, not a design specification.
| Clear Span | Typical Beam Size (Steel) | Typical Beam Size (Wood/LVL) |
|---|---|---|
| 6 ft | W6x9 | Double 2×6 |
| 8 ft | W6x9 | Double 2×8 |
| 10 ft | W8x18 | Double 2×10 / 9¼” LVL |
| 12 ft | W8x18 | Double 2×12 / 11⅞” LVL |
| 14 ft | W10x22 | Triple 2×12 / 11⅞” LVL |
| 16 ft | W10x22 | 14″ LVL |
| 18 ft | W12x26 | 16″ LVL |
| 20 ft | W12x26 | 16″+ LVL or glulam |
| 24 ft | W14x30 | Glulam recommended |
| 30 ft | W16x40 or larger | Glulam or steel recommended |
Beam Size by Floor Load
Beam recommendations vary based on the type and intensity of anticipated floor loads.
| Load Category | Typical Live Load | Recommended Beam Approach |
|---|---|---|
| Residential Floors | 40 psf | Standard wood or LVL beams |
| Roof Loads | 20–30 psf (varies by snow/region) | Lighter wood, LVL, or glulam beams |
| Storage Areas | 125 psf | Steel or heavy timber beams |
| Commercial Floors | 50–100 psf | Steel W-shapes, reinforced concrete |
| Industrial Floors | 150–250+ psf | Heavy steel W-shapes, engineered design |
Verify floor load capacity with our Slab Load Calculator and check deflection with the Concrete Slab Deflection Calculator.
Beam Size by Roof Application
Roof beam requirements vary significantly by roof shape and opening configuration.
| Roof Type | Typical Beam Approach |
|---|---|
| Flat Roofs | Steel W-shape or LVL, sized for full snow/live load |
| Pitched Roofs | Ridge beams in glulam or LVL, ridge board for simple framing |
| Vaulted Ceilings | Exposed glulam beams for structural and aesthetic function |
| Roof Openings (skylights, dormers) | Doubled headers in LVL or engineered lumber around opening |
Beam Size by Deck Construction
Deck beam sizing depends on joist span, post spacing, and elevation.
| Deck Type | Typical Beam Size |
|---|---|
| Residential Decks | Double or triple 2×10 (pressure-treated) |
| Elevated Decks | Triple 2×10–2×12 or steel beam for higher loads |
| Covered Decks | Sized larger for added roof dead load, often triple 2×12 |
| Balconies | Steel or engineered wood, cantilever design requires engineering |
Beam Size by Garage Door Opening
Common header/beam sizes by garage door width — verify with engineered calculation.
Planning Reference Only
These are general planning references. Garage headers carry significant roof and wall load — engineered verification is strongly recommended before construction.
| Opening Width | Typical Beam Size (planning reference) |
|---|---|
| 8-ft Opening | Double/triple 2×10 or 9¼” LVL |
| 10-ft Opening | 11⅞” LVL or W6x9 steel |
| 12-ft Opening | 11⅞”–14″ LVL or W8x18 steel |
| 16-ft Opening | 14″–16″ LVL or W8x18–W10x22 steel |
| 18-ft Opening | 16″ LVL or W10x22 steel |
Beam Size by Load Capacity
How beam material, span, shape, and support conditions combine to determine capacity.
| Load Category | Typical Beam Examples |
|---|---|
| Light Loads | Double 2×8 wood, 7¼” LVL, W6x9 steel |
| Medium Loads | Double 2×10–2×12, 11⅞” LVL, W8x18–W10x22 |
| Heavy Loads | Glulam, W12x26 and larger steel shapes |
What Drives Load Capacity
Beam material determines strength per unit area, span dictates bending moment, section shape governs stiffness (moment of inertia), and support conditions (simple span vs cantilever) change how load transfers to the structure. Check bearing pressure with our Concrete Bearing Pressure Calculator.
Beam Size by Building Type
Typical beam categories by overall building classification.
| Building Type | Typical Beam Approach |
|---|---|
| Houses | Wood, LVL, or light steel (W6–W8) |
| Garages | LVL or W6x9–W8x18 steel |
| Pole Barns | Solid timber or glulam |
| Warehouses | W12x26 to W24x68 steel |
| Office Buildings | W10x22 to W18x50 steel, reinforced concrete |
| Industrial Facilities | W14x30 and larger, HP shapes for foundations |
Beam Dimensions Chart
Comparing key structural dimensions across major beam categories.
| Beam Category | Beam Depth | Beam Width | Flange Width | Web Thickness |
|---|---|---|---|---|
| Steel W8x18 | 8.14 in | — | 5.25 in | 0.23 in |
| Steel W12x26 | 12.22 in | — | 6.49 in | 0.23 in |
| Reinforced Concrete | 12–24 in | 9–15 in | — | — |
| LVL Beam | 7¼–16 in | 1¾–7 in | — | — |
| Glulam Beam | 9–30+ in | 3⅛–8¾ in | — | — |
Steel Beam Designations Chart
Understanding common AISC steel shape designation letters.
| Designation | Shape Name | What It Represents |
|---|---|---|
| W | Wide Flange | Parallel flange faces, most common modern structural shape |
| S | Standard I-Beam | Tapered flanges, narrower than W-shapes, largely legacy use |
| M | Miscellaneous Shape | Lighter shapes not classified as W, S, or HP |
| HP | Bearing Pile Shape | Near-equal flange and web thickness, used for foundation piles |
| C | Channel | C-shaped cross-section, used for framing and bracing |
⭐ Beam Selection Guide
Quick decision reference matching project type to recommended beam with reasoning.
| Project | Recommended Beam | Why |
|---|---|---|
| Residential Floor | Double 2×10 or 11⅞” LVL | Cost-effective, meets typical residential spans |
| Roof | Glulam or LVL ridge beam | Handles snow/live load with exposed aesthetic option |
| Garage Opening | LVL or W8x18 steel | Supports roof/wall load over wide opening |
| Deck | Pressure-treated double/triple 2×10 | Weather-resistant, standard residential capacity |
| Commercial Building | W10x22 to W18x50 steel | Higher load capacity for commercial occupancy |
| Warehouse | W12x26 and larger | Long clear spans, heavy storage loads |
| Industrial Structure | W14x30+ or HP shapes | Handles heaviest structural and foundation loads |
For general project planning, see our How to Calculate Concrete guide and Concrete PSI Guide.
Beam Support & Bearing Length Guide
Minimum bearing requirements and common end support types.
| Support Type | Typical Minimum Bearing Length | Notes |
|---|---|---|
| Wood-to-Wood | 1.5 in | Standard for light residential beams |
| Steel Seats/Brackets | 2–3.5 in | Used for LVL and steel beam connections |
| Concrete Supports | 3–4 in | Common for beam pockets in concrete walls |
| Masonry Supports | 3–4 in | See our Masonry Block Size Chart for CMU wall bearing details |
When beams bear on reinforced concrete, cross-check reinforcement cover using our Concrete Cover Chart.
⭐ Visual Beam Size Guide
Engineering diagrams showing labeled cross-sections of common beam types.
Common Beam Selection Mistakes
Avoiding these errors prevents structural failures and costly rework.
Choosing Beam Size Based Only on Span
Span alone does not determine beam size — load, material, and support conditions all factor into a safe design.
Ignoring Live and Dead Loads
Failing to account for both permanent (dead) and variable (live) loads can lead to undersized, unsafe beams.
Insufficient Bearing Length
Beams resting on too little bearing surface can crush the support material or fail at the connection.
Improper Beam Orientation
Installing a beam on its weak axis dramatically reduces load capacity compared to proper orientation.
Overlooking Deflection Limits
A beam may be strong enough to avoid failure but still deflect excessively, causing cracked finishes or bouncy floors.
Assuming All Beam Materials Perform the Same
Steel, wood, LVL, and concrete beams behave very differently under load, fire, and moisture — material choice matters as much as size.
Skipping Engineered Verification
Using chart-based estimates without engineering sign-off on structural beams can violate code and create liability risk.
Contractor Worked Examples
Real-world beam selection scenarios for common project types. Pair these with our Beam Size Calculator and How to Calculate Concrete guide.
Garage Door Opening
Warehouse Beam
Frequently Asked Questions
📄 Download Beam Size Chart PDF
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