What an LVL beam span calculator can tell you
LVL, or laminated veneer lumber, is an engineered wood product used for beams and headers. A useful preliminary calculation starts with the span and the load the beam carries. This tool converts an area load in pounds per square foot into a line load on the beam, then estimates the bending and deflection properties required for a simple-span member.
How the estimate is calculated
line load w = psf × tributary width
maximum moment M = wL² ÷ 8
required section modulus S = M × 12 ÷ Fb
required inertia I = 5wL⁴ ÷ (384EΔ)
The deflection calculation uses a default serviceability limit of span divided by 360. The calculator reports the required section properties rather than pretending that one LVL size fits every project.
Example
For a 12 ft span carrying 50 psf across a 10 ft tributary width, the line load is 500 plf.
The simple-span maximum moment is approximately 9,000 lb-ft. The required section modulus depends on the allowable bending stress you enter.
Why LVL sizing needs more than span
Two beams with the same span can require very different sizes because the loads, support conditions, species or product grade, holes and notches, bearing length, lateral restraint, and allowable deflection can change the answer. Manufacturer span tables are based on the properties of specific products, so use this calculator as a screening step rather than a final beam selection.
Frequently asked questions
Can this calculate the exact LVL beam size?
No. It estimates the required section properties from simplified assumptions. The exact LVL product and its published properties must be checked before selection.
What is tributary width?
It is the width of floor or roof area whose load is transferred to the beam. The beam's line load is found by multiplying area load by tributary width.
What does section modulus mean?
Section modulus is a measure of a beam's bending capacity. A larger value generally means more resistance to bending for the same material stress.
Should I use this for a structural project?
Use it for preliminary planning only. A final structural member should be selected using the exact product data and applicable design requirements.
Is this the fastest way to calculate LVL beam size for a quick estimate?
For a rough first pass, yes. Enter your span and loading and it returns the section properties to look for. A final size should still be confirmed against a manufacturer's span tables.