Framing & structure
LVL & glulam beam calculator
Find the lightest LVL or glulam beam depth for a span and load, using typical published design values for each product.
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What an LVL and glulam beam calculator does
An LVL and glulam beam calculator finds the shallowest engineered wood beam that carries a given span and load. Enter the clear span, the tributary width, the loads and the product, and it returns the moment, shear and reactions, then steps each ply count (LVL) or width (glulam) through the product's standard depths until bending, shear and deflection all pass, and recommends the lightest section.
LVL and glulam carry much higher bending stresses than sawn lumber, and they come in deeper sizes, so they take over where built-up 2x beams stop. The calculator applies the LVL depth factor or the glulam volume factor, which lower the allowable stress on deep or long members, and the load duration factor for floor, snow or roof live load.
The product values are typical published figures for LVL 2.0E, glulam 24F-1.8E, EN 14080 GL24h and GL28h, and metric LVL. Each manufacturer publishes its own values and sizing tables, so confirm the final beam with the product literature or the supplier.
How to use the LVL & glulam beam calculator
- Choose Imperial or Metric. Imperial is the default, and your choice carries across the free tools.
- Enter the Clear span and the Tributary width of floor or roof the beam supports.
- Choose the Load case, then enter the Live or snow load, the Dead load and the Live-load deflection limit and Total-load deflection limit.
- Pick the Engineered product: LVL 2.0E in 1¾ in plies, glulam 24F-1.8E, GL24h or GL28h glulam, or metric LVL.
- Read the Lightest passing size, its utilisation and governing check, and the table of minimum depths for each ply count or width. Download the PDF or CSV and check the size against the manufacturer's tables.
Worked example
Imperial: A 16 ft span carrying 400 plf needs a 2-ply 1¾ × 11⅞ in LVL 2.0E, 91% utilised with deflection governing.
Metric: A 5 m span carrying 4.8 kN/m needs a 90 × 315 mm GL24h glulam, 86% utilised with bending governing.
LVL beam sizes by span
The table shows the minimum LVL 2.0E depth for each ply count carrying 400 lb per foot (8 ft of floor at 40 psf live and 10 psf dead) with L/360 live and L/240 total deflection. Deflection governs every row, which is typical for LVL beams at floor loads: adding a ply helps less than going one depth deeper.
Single 1¾ in plies are left out of the calculator because, at beam depths, they need continuous lateral support. Two plies fill a 2x4 wall, three a 2x6 wall.
| Clear span | 2 plies (3½ in) | 3 plies (5¼ in) | 4 plies (7 in) |
|---|---|---|---|
| 12 ft | 9¼ in | 9¼ in | 7¼ in |
| 16 ft | 11⅞ in | 11¼ in | 9¼ in |
| 20 ft | 16 in | 14 in | 11⅞ in |
| 24 ft | 18 in | 16 in | 14 in |
Glulam beam sizes by span
Glulam depths step in 1½ in laminations for western species. The volume factor reduces the allowable bending stress for long, deep, wide beams; at these loads deflection governs anyway, so the narrow 3⅛ in width is usually the lightest section and the wider beams buy depth.
| Clear span | 3⅛ in wide | 5⅛ in wide | 6¾ in wide |
|---|---|---|---|
| 12 ft | 10½ in | 9 in | 7½ in |
| 16 ft | 13½ in | 10½ in | 10½ in |
| 20 ft | 16½ in | 13½ in | 12 in |
| 24 ft | 19½ in | 16½ in | 15 in |
Metric glulam and LVL
Metric products are converted from characteristic values (EN 14080 for GL24h and GL28h, typical EN 14374 values for LVL) to an allowable-stress equivalent. The table shows the lightest passing section for 4.8 kN/m (2.4 m of floor at 1.5 kPa live and 0.5 kPa dead).
| Clear span | GL24h | GL28h | LVL (45 mm plies) |
|---|---|---|---|
| 4 m | 90 × 270 mm | 90 × 270 mm | 2 ply × 240 mm |
| 5 m | 90 × 315 mm | 90 × 315 mm | 2 ply × 300 mm |
| 6 m | 90 × 360 mm | 90 × 360 mm | 2 ply × 360 mm |
| 7 m | 90 × 450 mm | 90 × 405 mm | 2 ply × 400 mm |
LVL vs glulam vs built-up lumber
LVL is made from thin veneers glued with the grain parallel, so it is uniform, straight and strong, and it comes in 1¾ in plies that are nailed together on site. Glulam is laminated from dimension lumber into a single member, comes in wider sections and longer lengths, and can be left exposed in architectural grades. Built-up 2x beams use stock lumber but need more plies for the same span.
The values below are reference bending stress, shear and stiffness before size, volume and duration factors. They show why an LVL or glulam beam can be shallower than lumber at the same load.
| Material | Bending Fb | Shear Fv | Stiffness E |
|---|---|---|---|
| Douglas Fir-Larch No.2 (sawn) | 900 psi | 180 psi | 1,600,000 psi |
| LVL 2.0E (typical) | 2,600 psi | 285 psi | 2,000,000 psi |
| Glulam 24F-1.8E | 2,400 psi | 265 psi | 1,800,000 psi |
| GL24h (EN 14080, characteristic) | 24 MPa | 3.5 MPa | 11,500 MPa |
Worked example: a 16 ft LVL beam
A 16 ft clear span carrying 8 ft of floor at 40 psf live and 10 psf dead takes 400 plf, a 12,800 ft·lb moment and 3,200 lb at each end. A two-ply 1¾ × 11⅞ in LVL has a moment of inertia of 488 in⁴, so the 320 plf live load deflects it 0.48 in against an L/360 limit of 0.53 in: 91% utilised, with deflection governing.
A two-ply 11¼ in LVL would deflect past the limit, so 11⅞ in is the lightest two-ply depth. Three plies pass at 11¼ in and four at 9¼ in, useful when headroom is tight.
Who it is for and when to use it
Removing a bearing wall
Find the depth of a flush or dropped LVL beam for an open plan before an engineer specifies the product.
Garage door and wide openings
Size long headers where sawn lumber would need too many plies.
Exposed glulam beams
Compare glulam widths and depths for a visible ridge or floor beam early in design.
Metric projects
Get a first GL24h, GL28h or LVL section for a span in kN and metres.
Method, formulas & assumptions
Uniform load w = (live or snow + dead) × tributary width; M = wL²/8 and V = wL/2. Fb′ = Fb × CD × depth factor for LVL ((12/d)^0.136, typical 2.0E) or × volume factor for glulam (NDS 5.3.6: (21/L × 12/d × 5.125/b)^(1/x) ≤ 1, x = 10 western species or 20 Southern Pine; EN 14080 (600/h)^0.1 ≤ 1.1). Each width or ply count steps through the product's standard depths until bending, shear (1.5V ÷ Fv′A) and the live- and total-load deflection limits all pass; the lightest passing section is recommended.
Imperial inputs are converted with exact factors (1 ft = 0.3048 m, 1 lb = 0.45359237 kg, 1 US gal = 3.785411784 L) before the calculation runs in SI, then results are converted back.
Common mistakes to avoid
- Treating typical values as product values. LVL grades from different manufacturers differ; use the supplier's tables for the final size.
- Mixing ply widths or products in one beam.
- Forgetting the bearing length. Engineered beams often need longer bearing or a post cap to keep the reaction within the compression perpendicular to grain limit.
- Notching or drilling an engineered beam outside the manufacturer's allowed zones.
- Leaving out the beam's self-weight on long spans.
Scope & limits
Typical values only: LVL and glulam properties vary by manufacturer and layup, so confirm with the product literature or the supplier's sizing software. Simple span, uniform load, braced compression edge, dry service. Beam self-weight, point loads, bearing length, holes, cantilevers, connections and fire are not included, and this is not an engineered design.
Frequently asked questions
What size LVL do I need for a 16 ft span?
Carrying 8 ft of floor at 40 psf live and 10 psf dead (400 plf), a two-ply 1¾ × 11⅞ in LVL 2.0E passes with typical values at 91% utilisation. Confirm with the manufacturer's tables.
How far can a 2-ply 11⅞ LVL span?
At 400 plf with L/360 live and L/240 total deflection, a little over 16 ft with typical 2.0E values. Lighter loads allow more, and the manufacturer's span tables give the exact figure.
Is LVL stronger than glulam?
Typical LVL 2.0E has a slightly higher bending stress and stiffness than glulam 24F-1.8E, but glulam comes wider, so the lightest beam depends on the width you can use.
What is the glulam volume factor?
An NDS reduction for large glulam beams: (21/L × 12/d × 5.125/b)^(1/10) for western species, never more than 1.0. Long, deep and wide beams get a lower allowable bending stress.
Why are single LVL plies not offered?
A single 1¾ in ply at beam depths is slender and needs continuous lateral support, so the calculator starts at two plies.
Does the calculator replace the manufacturer's software?
No. It gives a preliminary size from typical values. Manufacturer software and tables cover bearing, holes, point loads and their own design values.
Do I need an account to download the result?
No. All calculations, local file processing and exports on this page are free, without an account.
Where are my inputs stored?
The tool keeps inputs in this browser tab. It does not upload them or create a cloud copy. Save or download anything you want to keep before leaving the page. Standard site analytics may operate independently of the tool.
Can I work in metric instead of imperial?
Yes. Use the Imperial / Metric switch above the inputs. Imperial (feet, inches, pounds, gallons) is the default; switching converts every dimensional field and result, and your choice is remembered across the free tools in this browser.
Further reading
- Renovations and extensions
- Ground snow load explained
- All framing & structure tools
- All free architecture & construction tools
- Harth resource library
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