Laminated Veneer Lumber (LVL) is engineered lumber made by laminating thin veneers of softwood with structural adhesives, with the grain of all veneers running parallel to the length. The result is a beam that is stronger, stiffer, and more dimensionally stable than dimension lumber, with predictable structural properties that allow longer spans at the same depth. The LVL beam span calculator above takes span, load type, and tributary width as inputs and returns a starting LVL size for residential framing.
The same tool serves several jobs depending on what you call it. As an LVL beam span calculator (the most common search phrasing — focused on the maximum allowable span for a given LVL size), it returns the span limit for any beam configuration. As an LVL span calculator more generally, an LVL span calculator app for mobile use, or simply as an LVL calculator, LVL beam calculator, or LVL load calculator, it works as a first-pass sizing tool for residential beams. The same arithmetic also serves as a beam span calculator for non-LVL solid-sawn beams (with adjusted load tables), a wood beam span calculator for any species and grade, a wood beam calculator for general beam-sizing work, a header span calculator for door and window header sizing, a roof beam calculator for ridge beams and roof support beams, and a timber beam calculator for traditional timber framing. A glulam beam calculator runs nearly the same math with different design values; LVL rafter span tables and LVL beam size calculator span tables both use the same underlying formulas. An LVL weight calculator is a separate calculation derived from the same dimensions (LVL density × cross-section × length).
The calculator above produces a first-pass starting size for residential LVL beams based on span, load type, and tributary width. It is reference only — not engineered design. Real-world LVL specification depends on E-rating, ply count, deflection limits, connection details, and applicable code load combinations. For any beam outside the IRC R602.7 prescriptive header tables, you need a structural engineer to size it.
LVL Beam Sizing Reference
A first-pass starting size for residential LVL beams. Always confirm with an engineer.
Inputs
Half the distance to the next supporting beam or wall, on each side
Results
Starting size
2× 1.75″ × 14in LVL (doubled)
What LVL is and why it is used
LVL is one of the four major engineered wood products used in residential framing. The others are I-joists (composite floor joists with OSB webs and lumber flanges, see truss joist span chart for sizing), Glulam (glue-laminated timber, used for very long spans and architectural applications), and PSL (parallel strand lumber, used for heavy beam applications). LVL fills the middle ground — most residential headers and floor/roof beams that exceed dimension lumber's capacity are spec'd in LVL. For dimension-lumber floor joist sizing (a different product from I-joists), the floor joist calculator on this site runs the IRC R502 math.
The advantage of LVL over dimension lumber: at the same depth, an LVL beam spans roughly 50-100% farther than a comparable Douglas-fir or southern yellow pine sawn beam, depending on grade. An 11.875-inch deep LVL beam can carry typical residential loads over a 12-14 foot span; the same span in dimension lumber would require either a 14-inch LVL or a doubled 2x12 (which is structurally questionable and difficult to detail).
LVL also produces less in-place dimensional change than dimension lumber. Lumber shrinks 4-7% across the grain as it dries from green to in-service moisture content, leading to drywall cracks, door binding, and floor squeaks. LVL ships at in-service moisture content and shrinks less than 1% — meaningfully less drywall and finish problems over time.
LVL is essentially a manufactured replacement for solid-sawn dimension lumber where dimension lumber is too weak, too short, or too dimensionally unstable. The cost premium (LVL is typically 2-3× more expensive per linear foot than equivalent dimension lumber) is offset by the longer spans, smaller member sizes, and predictable performance. For most residential applications where dimension lumber would be marginal, LVL is the standard upgrade.
Standard LVL sizes and grades
LVL is sold in standard depths matched to dimension-lumber depths so the beams nest cleanly with surrounding framing. Common depths: 5.5 inches (matches 2x6), 7.25 inches (matches 2x8), 9.25 inches (matches 2x10), 11.875 inches (matches 2x12), 14 inches, 16 inches, and 18 inches. Custom depths up to 24 inches are available from major manufacturers.
LVL ply thickness is typically 1.75 inches per ply. Single-ply LVL (1.75 inches wide) is used for narrow applications like nailers and short-span beams. Double-ply (3.5 inches wide, two 1.75-inch plies bolted or nailed together) is the most common configuration for residential beams. Triple-ply (5.25 inches wide) handles heavier loads or longer spans where doubled LVL is insufficient.
LVL grades are specified by E-rating (modulus of elasticity in millions of psi) and Fb (bending strength in psi). Common residential grades: 2.0E (Microllam by Trus Joist), 1.9E (Versa-Lam by Boise Cascade), 1.8E and 2.1E for premium applications. Higher E-ratings handle longer spans at the same depth. Grade affects the calculated span; always verify the calculator inputs match your actual LVL grade.
LVL lengths up to 60+ feet are available for special-order applications. Standard stocked lengths are typically 12, 14, 16, 18, 20, and 24 feet at most retail lumber yards. Longer beams require custom order with 1-3 week lead time.
| LVL depth | Matches | Single-ply (1.75") | Double-ply (3.5") | Typical residential use |
|---|---|---|---|---|
| 5.5" | 2×6 | Nailers, short headers | Headers up to ~6 ft span | Door/window headers |
| 7.25" | 2×8 | Short floor beams | Headers up to ~8 ft | Window headers, short floor beams |
| 9.25" | 2×10 | Floor beams up to ~10 ft | Floor/roof beams up to ~12 ft | Floor beams, mid-span ridge beams |
| 11.875" | 2×12 | Floor/roof beams up to ~12 ft | Floor/roof beams up to ~14 ft | Most common residential beam size |
| 14" | Custom | Floor/roof beams up to ~14 ft | Floor/roof beams up to ~16 ft | Long spans, heavy loads |
| 16" | Custom | Floor/roof beams up to ~16 ft | Floor/roof beams up to ~18 ft | Long-span ridge beams, garage door headers |
| 18" | Custom | Floor/roof beams up to ~18 ft | Floor/roof beams up to ~20 ft | Open-plan floor beams, long ridge beams |
| 24" (custom order) | Custom | Per engineering | Per engineering | Specialty long-span applications |
LVL beam span calculator inputs and LVL rafter span tables
A complete LVL beam span calculator takes the following inputs: (1) beam span (clear distance between supports, in feet), (2) total load (dead + live, typically 30-60 psf for residential), (3) tributary width (the floor or roof width supported by the beam, in feet), (4) LVL grade (E-rating and Fb), (5) deflection limit (typically L/360 for floors, L/240 for roofs), (6) ply count (single, double, triple).
The calculator output is the smallest LVL size that meets both bending strength and deflection requirements for the given inputs. For typical residential conditions: 11.875-inch double LVL (3.5 × 11.875) handles 12-foot spans at 50 psf load with 14-foot tributary; 14-inch double LVL handles 16-foot spans at the same load. Always compare the calculator output against the actual LVL beam size calculator span tables published by the manufacturer for your specific product.
LVL rafter span tables are a specialized application of the same calculator. Roof rafters use lower load combinations (snow live load typically 20-50 psf) and may use L/240 deflection rather than L/360. The same beam that spans 16 feet as a floor beam might span 18-19 feet as a rafter at the same depth. Manufacturer-published LVL rafter span tables specify the difference for each product. For dimension-lumber rafter sizing (different math from LVL), the rafter length calculator on this site handles the standard residential cases separately.
For headers (door and window framing): the header span calculator math runs the same way but with shorter spans (typically 3-12 feet) and concentrated loads from the wall sections above. IRC R602.7 includes prescriptive header tables for dimension lumber and double LVL up to 12-foot spans; longer or heavier-load headers need engineering review. The header span calculator on this site handles the standard residential cases.
For roof beams (cathedral ceilings, ridge beams, eave beams): the roof beam calculator portion handles the longer spans and snow load combinations typical of residential roofs. A typical residential ridge beam at 18-foot span with 14-foot tributary at 50 psf load comes out to a 1.75 × 11.875 double LVL. For longer spans, the calculator suggests 14-inch or 18-inch depths.
LVL load calculator: tributary width and load combinations
The LVL load calculator portion determines the total load the beam must carry. Total load = dead load + live load. Dead load is the weight of the structure itself (framing, sheathing, roofing, ceiling, finishes); live load is the variable load (people, furniture, snow, wind). Both contribute to the design load.
Typical dead load values: 10 psf for typical floor systems with 3/4-inch subfloor, dimension-lumber joists, and dropped ceiling. 15 psf for floor systems with hardwood, tile, or stone finishes. 20 psf for floor systems with concrete topping. 7-10 psf for typical asphalt-shingle roof. 12-15 psf for tile roof systems. 20-25 psf for ceramic tile and slate.
Typical live load values: 40 psf for residential floor (IRC requires 40 psf for occupied areas; 30 psf in attics with limited storage). 30 psf for non-storage attics. 20-50 psf for snow load (varies by climate zone — verify against your local snow load map). 20 psf minimum live load for typical residential roof.
Tributary width is the width of the floor or roof tributary to the beam (the area whose load the beam carries). For a beam supporting joists running perpendicular to it, tributary width = half the joist span on each side. For a 24-foot-wide floor with the beam in the middle: tributary width = 12 feet on each side (24 feet total tributary on the beam).
Linear load on the beam = total load (psf) × tributary width (ft). For 50 psf total load and 14 feet tributary: 50 × 14 = 700 lbs per linear foot of beam. The LVL load calculator uses this linear load to determine bending moment and deflection, which determine the required beam size.
LVL vs. glulam beam calculator: when to use which
Glulam (glue-laminated timber) and LVL are similar engineered-wood products with different applications. A glulam beam calculator runs the same math but with different design values: glulam typically has lower bending strength than LVL at the same depth (Fb typically 2,400-2,800 psi for glulam vs. 2,600-3,300 psi for LVL), but higher visual quality (the glulam shows the grain of the lamination plies, which is often a desired aesthetic in exposed cathedral ceilings).
LVL is the cost-effective choice for hidden structural applications: floor beams, headers, and any beam that will be covered with finish (drywall, ceiling, etc.). Glulam is the choice when the beam is visible (cathedral ceilings, post-and-beam construction, exposed-beam architectural styles). The cost difference: glulam typically runs 30-60% more per linear foot than LVL at the same capacity.
For a typical 18-foot-span ridge beam with 14-foot tributary at 50 psf load: LVL solution is 1.75 × 11.875 double ($200-300 in materials). Glulam equivalent is 6.75 × 12 ($300-450 in materials, with the visual upgrade). The structural performance is comparable; the choice is between cost and aesthetic.
A timber beam calculator handles solid-sawn timber framing (Douglas fir 6x12, 8x14, etc., used in traditional timber-frame construction). Solid timber has lower design values than LVL or glulam — typically Fb of 1,000-2,000 psi depending on species and grade. For the same span and load, a solid timber beam needs to be larger than the LVL or glulam equivalent. The math still uses the same formulas; just substitute the lower design values.
When the calculator is enough vs. when engineering is required
The LVL beam span calculator (and any first-pass beam calculator) is appropriate for: typical residential spans under 20 feet, uniformly distributed loads only, no concentrated point loads, standard load combinations, and conditions covered by the IRC R602.7 prescriptive header tables. For these cases, the calculator output gives a starting size that's likely correct. Final verification is still prudent — verify against the manufacturer's span tables for your specific LVL grade.
Engineering review is required for: spans over 20 feet (varies by jurisdiction), concentrated point loads (from posts, columns, large windows, dormers, equipment), unusual load combinations (heavy snow, seismic zones, wind exposure D), multi-span continuous beams (more than 2 supports), beams with cantilevers, and any non-prescriptive condition. The cost of engineering review ($300-1,500 for residential beam design) is small relative to the consequences of an undersized beam (sagging, structural failure, expensive remediation).
For most residential conditions, the workflow is: (1) use the calculator above to get a starting size, (2) verify against the manufacturer's published span tables for your specific LVL product, (3) if the conditions are non-prescriptive (long spans, concentrated loads, unusual loading), get engineering review before purchasing materials. Skipping the engineering review on non-prescriptive conditions is the most common cause of LVL sizing failures in residential construction.
IRC R602.7 prescriptive header tables cover standard door and window headers in light-frame construction. The tables specify allowable spans for typical dimension lumber and LVL headers under typical residential loads. For headers exactly matching the prescriptive conditions, no engineering review is needed. For any deviation (longer spans, heavier loads, non-standard wall configurations), engineering review is mandatory.
LVL connection details and installation
Multi-ply LVL beams are connected by either nails or bolts depending on the load. Nails (typically 16d common nails at 12 inches OC, staggered) work for typical residential loads where the connection only needs to keep the plies aligned. Bolts (typically 1/2-inch diameter at 16-24 inches OC, staggered) are needed for heavier loads or where engineering specifies bolted connections.
End-bearing requirements: LVL beams require minimum bearing length at supports, typically 1.5-3 inches depending on the beam size and end-grain capacity. The exact requirement is specified by the manufacturer and depends on the bearing surface (post, wall plate, beam pocket). Insufficient bearing causes crushing and failure at the support.
Connection to other framing: LVL beams typically connect to perpendicular framing (joists, rafters) using metal hangers (Simpson HU, Simpson LUS, or similar). The hanger size and capacity must match the load; a hanger sized for a 2x10 floor joist is not adequate for a 2x14 LVL.
Lateral bracing: LVL beams in floor or roof systems are typically braced laterally by the perpendicular framing (joists or rafters) bearing into them. For beams without continuous lateral bracing, additional bracing may be required to prevent lateral-torsional buckling — the engineer's design specifies any lateral bracing requirements.
Holes and notches in LVL: LVL manufacturers publish strict rules for allowable holes and notches. In general: holes are allowed in the middle third of the depth (vertically) and away from the supports (horizontally). Notches are typically NOT allowed in the tension face of the beam. Always verify against the manufacturer's technical bulletin before drilling or notching any LVL beam in service.
How we sourced these recommendations
LVL specifications and design values reflect typical 2026 published manufacturer data from Trus Joist (Microllam), Boise Cascade (Versa-Lam), and Louisiana-Pacific (LVL). Specific values vary by product line and grade; always verify against the manufacturer's technical bulletin for your specific product before final design. The calculator inputs reflect typical residential load combinations under the 2024 International Residential Code; specific projects with non-prescriptive conditions require engineering review.
Pricing figures reflect 2026 typical residential pricing in major U.S. metro markets. Pricing varies by region, distributor relationships, and product availability. Recommendations are reviewed annually and updated whenever industry pricing or product specifications change materially. For project-specific design, defer to a licensed structural engineer or architect using the actual manufacturer's design tools.
Need to run the numbers?Use the free roof pitch calculator on the home page to convert pitch to angle, calculate rafter length, or estimate roof area in any unit.