Beam Calculations and Header Sizing by a PE
Beam calculations for LVL, glulam, steel and lumber members, with posts and footings checked, sealed by a licensed PE for your permit.
- Stamped by a PE licensed in your state
- Built to IBC, IRC and local amendments
- Plan-check comments answered
The right beam, proven by calculation
Beam calculations are the most common structural document a building department asks for. Any time a beam or header carries more than the code tables cover, whether it supports a floor, a roof, a girder truss or another beam, the plan reviewer wants to see the loads, the member size and the proof that it works. PE Engineer prepares those calculations and seals them with a PE licensed in your state.
We size beams and headers in dimensional lumber, LVL, PSL, glulam and structural steel. Each calculation follows the load from where it starts to where it ends, so the post under the beam and the footing under the post are checked too. That is the part most quick sizing tools skip and most plan reviewers look for.
The result is a short, clear calculation package and a detail sheet your framer can build from. If your plans are already drawn, we add the beam information to them. If not, we provide a standalone sheet with the beam, posts, connections and notes.
What you receive
- Load and tributary width summary
- Beam and header size with grade
- Post and column sizing
- Bearing and connection details
- Footing check under point loads
- PE stamped calculations and detail sheet
Beams and headers we calculate
Every member is checked for bending, shear, deflection and bearing under the loads it will actually carry.
Floor beams
Flush and dropped beams supporting floor joists, bearing walls above or a second story, sized so the floor stays stiff and level under everyday use.
Window and door headers
Headers in bearing walls that carry roof, ceiling and floor loads, including girder truss reactions that land directly over an opening and overload a table header.
Garage door headers
Long-span headers over single and double garage doors, checked for roof and floor loads above and coordinated with the door manufacturer's required headroom.
Ridge and hip beams
Structural ridge beams for vaulted ceilings without rafter ties, plus hip and valley members carrying jack rafters, with uplift connections at each end.
Steel beams and flitch plates
Wide-flange steel beams and flitch beams for long spans or shallow depth limits, with bearing plates, bolts and wood nailers detailed for the framer.
Beams supporting other beams
Girders that pick up other beams or posts, where concentrated loads stack and table sizing no longer applies. These need careful load tracing and connections.
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Send your drawings or describe the project. A licensed engineer reviews it and sends a clear, fixed-fee proposal, often within hours.
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- Reviewed by a licensed PE
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What beam calculations show the plan reviewer
A plan reviewer checks a beam calculation to confirm three things: the loads are right, the member works, and the load has somewhere to go. Our calculation packages are organized around exactly those questions.
- Loads. Dead load from the roof, floors and walls above, live load for the occupancy, snow load from ASCE 7 for your address, and any point loads from posts, girder trusses or other beams. Tributary widths are shown so the reviewer can follow the math.
- Member design. Bending, shear and deflection checks to the NDS for wood or AISC 360 for steel, with the grade, species or product line called out.
- Reactions. The load delivered to each end of the beam, carried into post sizing, bearing length and the footing below.
We keep the package short and readable. A single header calculation might be two or three pages. A full remodel with several beams is organized member by member with a summary table at the front, so the reviewer and your contractor can find any beam quickly.
The calculations come with a detail sheet showing the beam, its bearing, the post below and the connection hardware. Some jurisdictions accept the calculation alone, while others want the information on a drawing. We provide both so the submittal is complete either way.
Choosing the beam: lumber, LVL, glulam or steel
The best beam is the one that fits the span, the depth you have available and your budget. We size the options and recommend the one that makes sense for your project.
Dimensional lumber
Built-up 2x members are inexpensive and easy to install for short headers and modest loads. They run out of capacity quickly as spans grow.
LVL and PSL
Engineered lumber is stronger, straighter and more consistent than sawn lumber. LVL is the most common choice for flush floor beams and long headers. Multi-ply LVL beams need a specific nailing or bolting pattern so the plies share load, and we specify it on the drawing.
Glulam
Glulam handles long spans, can be ordered with camber, and is often chosen where the beam will be exposed and appearance matters.
Structural steel
When the span is long and the depth is limited, a wide-flange steel beam is often the only member that fits inside a floor. Steel requires bearing plates, bolted wood nailers for attaching joists, and more planning for installation. Our steel structure design team details the connections. A flitch beam, a steel plate bolted between wood members, is a lighter middle ground for some retrofits.
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- Reviewed by a licensed PE
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Header beam calculations for windows, doors and garages
The IRC includes header tables that cover many ordinary window and door openings in bearing walls. Those tables assume a specific set of conditions: a limited building width, standard roof and floor loads, and uniform load from above. Header beam calculations are needed when any of those assumptions break down.
- A girder truss lands over the opening and drops a large concentrated load on the header.
- The opening is wider than the tables cover, such as a 16-foot or 18-foot garage door or a wide sliding door.
- A second floor and roof both bear on the header, or a heavy roof covering such as tile adds load.
- Ground snow loads at your site exceed what the tables were built for.
- A tall wall or a window wall leaves little room for the jack and king studs the header needs.
We size the header, specify the number of jack and king studs at each end, and check bearing on the plate below. For garage door headers we also confirm that the header depth leaves the headroom the door track needs, which avoids a costly surprise at installation. Where large openings remove wall bracing, we flag it so the lateral design can be adjusted in the framing plans.
Following the load: posts, bearing and footings
A beam is only as good as what holds it up. Every beam reaction must travel down through a post or stud pack, through each floor level, and into a footing that can carry it. Skipping this step is one of the most common reasons beam calculations get returned at plan review.
For each support we check:
- Bearing length, so the beam does not crush the top of the post or the wall plate. Wood crushes across the grain long before it fails along it.
- Post capacity, including buckling for tall or unbraced posts, with the post size and grade specified.
- Continuity through the floors below, with solid blocking or squash blocks so the load does not punch through joists or rim boards.
- The footing, sized for the concentrated load and your soil. Existing slabs and continuous footings often cannot take a new point load without a new pad footing.
When a new footing is needed, we design it in the same package so your contractor can saw-cut and pour without waiting on a second engineer. Larger foundation changes are handled through our foundation design service. Connections close the loop: post caps, post bases, hangers and straps are called out by type, so the inspector sees a complete load path.
You likely need this if
- A beam or header exceeds IRC tables
- A girder truss lands on a header
- You are widening a garage door
- A beam supports another beam or post
- Your plan reviewer asked for beam calcs
- You are installing a steel or flitch beam
How it works, start to finish
From your first message to stamped drawings, you work directly with the engineering team.
- 1Share your projectSend the address, scope and any drawings, photos or plan-check comments. Two minutes is enough.
- 2Receive a fixed-fee proposalAn engineer reviews the scope and replies with a firm price and delivery date for your beam & header calculations drawings.
- 3Engineering and draftingWe run the calculations and prepare drawings to the codes your jurisdiction enforces, checked before sealing.
- 4Stamped set deliveredYou receive a sealed PDF set ready to submit, and we answer any plan-check comments within scope.
Codes and standards for beam design
Beam and header calculations follow the codes your jurisdiction has adopted and the published design values for each product:
- International Residential Code (IRC) and International Building Code (IBC)
- ASCE 7 for dead, live, snow and wind loads
- AWC National Design Specification (NDS) for Wood Construction
- AISC 360, Specification for Structural Steel Buildings
- ACI 318 for footings under new point loads
- ICC-ES evaluation reports and manufacturer design values for engineered lumber
How licensing works. Engineering drawings must be sealed by a Professional Engineer licensed in the state where your project is located. PE Engineer works with a network of state-licensed PEs, so every set is reviewed and stamped by an engineer with an active license in the state where your project is located. Their name and license number appear on the seal, exactly as your building department requires.
Related services
Load-Bearing Wall RemovalOpen up your floor plan safely. Beam, post and footing design for removing a bearing wall, with stamped plans your building department will review.Explore More
Framing PlansFloor, wall and roof framing plans with joist, rafter, header and shear wall design, sealed by a licensed PE for permit.Explore More
Steel Structure DesignSteel beams, columns, moment frames, braced frames and connections designed to AISC standards and stamped for residential, commercial and industrial permits.Explore MoreFrequently asked questions
Can my lumber yard size the beam instead?
For simple cases, some building departments accept a sizing printout from the lumber supplier’s software. Many do not, especially when the beam carries loads from more than one level, supports another beam, or needs a post and footing check. A PE stamped beam calculation covers all of that in one document the reviewer can follow.
What size beam do I need to span 20 feet?
There is no safe rule of thumb, because the answer depends on what the beam supports, the tributary width, snow load, the material and how much depth you have. Two 20-foot beams in the same house can need very different sizes. A quick calculation gives you the right member instead of an oversized or undersized guess.
What is the difference between a flush beam and a dropped beam?
A flush beam sits within the depth of the floor or ceiling joists, which hang from it on hangers, leaving a flat ceiling. A dropped beam sits below the joists, which rest on top of it. Flush beams look cleaner but usually need a deeper or stronger member and more hardware.
Do headers in non-bearing walls need calculations?
Usually not. A wall that carries no roof, floor or ceiling load needs only a nominal header. The key is confirming the wall is truly non-bearing, which is not always obvious in older homes or houses with trusses that have interior bearing points. We can confirm it from photos and plans.
What do you need to calculate my beam?
The address, a floor plan or sketch showing the beam location and span, what is above it such as roof, attic or another floor, the roofing material, and photos of the existing framing. If you already have a beam size in mind, tell us and we will check it.
How fast can I get stamped beam calculations?
Single beam and header calculations are usually among our quickest jobs, and most are delivered within a few business days. Rush service is available when a framing inspection or plan review deadline is close. Plan-check comments on our calculations are answered at no extra charge.
Get your free beam & header calculations proposal
Tell us where the project is and what you need. Attach any drawings, photos or plan-check comments. A licensed engineer reviews every request.
- Upload your filesPlans, sketches, photos or comments
- Get a fixed-fee proposalUsually the same day
- Receive stamped drawingsSealed by a PE licensed in your state