Joist Hanger Selection Calculator

About the Joist Hanger Selection Calculator

Joist hangers are metal connectors that provide a code-approved method for attaching floor joists, ceiling joists, and deck joists to beams and headers without relying solely on toenails. Selecting the correct hanger ensures the connection can carry the designed loads safely.

This joist hanger selection calculator helps you choose the right hanger model based on your joist size, the load it must carry, and whether the connection is square or at an angle. It references common residential hanger types similar to Simpson Strong-Tie's LUS and LU series.

Proper hanger selection is critical for structural integrity, especially at openings in the floor where headers carry multiple joist loads, and on decks where connections are subject to inspection. Using the wrong hanger or underloading a connection can lead to floor sag, squeaks, or worse.

When This Page Helps

Building codes require engineered connections for joist-to-beam attachments. This calculator quickly identifies the correct hanger size and confirms its load capacity meets your design requirements, saving time flipping through manufacturer catalogs.

How to Use the Inputs

1. Select the joist size (2×6, 2×8, 2×10, or 2×12).
2. Enter the load per joist in pounds (or use the default for standard residential).
3. Select the connection type (face mount or top flange).
4. Select the angle if the joist meets the beam at a skew (0° for square).
5. Read the recommended hanger model and its allowable load capacity.

Example Calculation

Tips & Best Practices

• Always use the manufacturer-specified nail type and quantity—substituting nails voids the rated capacity.
• Use joist hanger nails (short, fat shanks) not standard framing nails in hanger holes.
• For skewed connections of 45° or more, use adjustable or skewable hangers.
• Double-check that the hanger seats the joist fully—gaps at the bottom reduce capacity.
• Use top-flange hangers where you can't access the beam face for nailing.
• Galvanize or use stainless steel hangers for outdoor, deck, and treated lumber applications.

Common Joist Hanger Types

The most common residential joist hangers are the LUS (face-mount) and?"LU series. LUS26, LUS28, LUS210, and LUS212 handle 2×6 through 2×12 joists respectively. Double-joist hangers (LUS2-series) are available for doubled trimmers at openings.

Hanger Installation Best Practices

Seat the joist fully in the hanger before nailing. Fill every hole with the specified nail—empty holes reduce the rated capacity proportionally. Bend the tabs tight against the joist and ensure the hanger flanges are flush against the beam face with no gaps.

When to Consult an Engineer

For point loads exceeding standard hanger capacity, multi-ply beams, steel beams, or unusual angles, consult a structural engineer. They may specify a custom welded bracket, a concealed hanger, or a bolted connection that can't be selected from a standard catalog.

Frequently Asked Questions

• Can I use nails instead of joist hangers?

  Toenailing is code-approved for some connections, but joist hangers provide significantly more capacity and consistency. Most building departments require hangers for floor joist-to-beam connections and all deck connections.

• What nails go in joist hangers?

  Use 1-1/2″ x .148″ joist hanger nails (also called 10d x 1-1/2″ short). Never use standard 16d sinkers, framing nails, or drywall screws—they don't fit the holes and lack the shear capacity.

• Do I need hangers on both ends of a joist?

  Hangers are required wherever a joist bears on a beam or header without resting on top. If the joist sits on top of a beam, hangers aren't needed at that end, though hurricane ties may be required.

• What is the difference between LUS and LU hangers?

  LUS hangers have a sloped seat for top-flange mounting and are used where the joist attaches at the same height as the beam top. LU hangers are face-mount types where the joist hangs below the beam top.

• Can I use galvanized hangers with treated lumber?

  Standard galvanized (G90) hangers work with most ACQ and CA-treated lumber. For saltwater exposure or ground contact, use stainless steel or ZMAX-coated hangers as recommended by the connector manufacturer.

• How do I know the load on each joist?

  Multiply the tributary width (half the spacing to each side) by the joist span and the total load per square foot (typically 50 psf for residential floors: 40 live + 10 dead). For example, a joist at 16″ OC spanning 12 feet carries (1.33 ft)(12 ft)(50 psf) = 800 lbs per end.