Beam calculator.
Choose wood or engineered lumber. Explore sections, loads, deflection and hole locations, all in feet, inches and pounds.
Example inputs. Preliminary elastic analysis and limited hole-geometry review; not a permit, construction, connection, or complete code design. Tool terms.
Define the beam
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.
Beam response
Left reaction—
Right reaction—
Maximum absolute shear—
Maximum absolute moment—
Maximum downward deflection—
Section & stress
—
—
—
Strength comparison not enabled.
Opening review
—
Response and stress charts use the uncut gross section. A hole can affect shear, stress concentration and stiffness; this tool does not quantify those local effects.
Upward reactions are positive. Sagging moment is positive; the cantilever fixed-end moment is hogging. Downward deflection is positive. Charts show the entered beam, not allowable limits.
Response diagrams
From the left support or fixed end, x = 0.
Bending moment lb·ft
Downward deflection in
An interior point load creates a vertical jump in shear. A point load exactly at a support is included in that support reaction and causes no beam-interior response by itself. Export the station data for exact values; plotted lines are a visual guide.
See what depth changes.
Same material, width, plies and loads. Gross-section response only; no bearing, stability or connection approval. Choose a row to explore it. CSV includes this comparison and selected-section station results.
| Actual depth | I (in⁴) | Total deflection | Live deflection | Bending stress | Explore |
|---|
Know what’s behind the result.
All dimensions and outputs use US customary units: feet and inches, pounds, psi, and lb·ft. Reactions follow static equilibrium. Bending deflection integrates the moment equation with constant EI. Weyerhaeuser presets add rectangular shear deformation using published G and a 5/6 shear correction; other materials remain bending-only. Dead and live loads superpose; live-load deflection is calculated separately. For rectangular plies, I = nbd³/12 and S = nbd²/6.
Material choices supply reference stiffness, not a design rating. Sawn presets use AWC 2024 dimension-lumber E values. Engineered-lumber presets identify the manufacturer and publication. Wet conditions, temperature, load duration, creep, shear deformation, bracing, bearing, connections and product availability need separate review. An opening is reviewed geometrically only and does not reduce gross I in the response model.
Manufacturer sizing tables apply to specific spans, loads, bearings and bracing. A joist span table, open-web steel joist table, or historical steel load chart is not a universal beam-sizing rule. This workbench does not select steel shapes or approve engineered-wood drilling.
AWC 2024 design values ↗ · Weyerhaeuser TJ-9000 · July 2026 ↗ · Deep PSL TJ-7001 ↗ · Boise Cascade Western guide ↗ · Manufacturer sizing lookup ↗
Why actual dimensions?
A nominal 2 × 10 dry member is 1½ × 9¼ inches. Stiffness depends on depth cubed, so using nominal dimensions can materially understate deflection.
Does a ratio below 1 mean my beam is approved?
No. A deflection comparison checks only your selected target. Optional stress ratios compare gross elastic stresses with allowable values you supply. They do not check the full member, connections, bearings, holes, load combinations or local requirements.
Preliminary planning only. Using this tool does not engage Spacial for your project. Free-tool terms.
SPACIAL / PROJECT SUPPORT
Need help with your project?
More tools.
All tools
Site analysis
Explore sun, shadows, climate and site hazards, then sketch your lot.Open the tool
Electrical layout
Trace walls, place lighting and appliances, and connect every load to a main panel.Open the tool
Panel planner
Turn rooms, lighting and appliances into a service-load estimate and breaker schedule.Open the tool