Joist Hanger Calculator
Joists that butt into a ledger or a flush beam hang in metal joist hangers, and every hole in the hanger gets the specified nail. Enter the deck length, the joist spacing, the joist size and how many ends of each joist sit in hangers. The calculator counts the hangers, names the matching Simpson Strong-Tie LUS face-mount model and counts the 10d nails for the header and the joist.
What you'll need
As an Amazon Associate I earn from qualifying purchases.
25 Pack 2x10 Joist Hangers with Screws for Wood, Galvanized Face Mount
$39.99
Check price on Amazon
FrogTape Pro Grade Deck and Joist Flashing Tape, 1.89 in x 50 Feet, Black
Save 17%
$18.75Typical price:: $22.55
BNUOK Lag Screws #14 x 6 Inch, (1lb, 20pcs) Heavy Duty Construction Structural Exterior Wood Timber Screws, Torx Drive Washer Head Rust Resistant Black Epoxy Coated, with T30 Star Bit
$8.99
Check price on Amazon
CRAFTSMAN 25-Ft Tape Measure with Fraction Marketing, Retractable, Manual-Locking Blade (CMHT37443S)
Save 35%
$12.98Typical price:: $19.98
Prices and savings as of Oct 1, 2026, 4:35 AM UTC. Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product.
Shopping for someone? See our backyard gift guide for deck builders & DIYers.
LUS hanger nails by joist size
Simpson Strong-Tie face-mount LUS schedule, 0.148 × 3 in (10d common) nails.
| Joist | Hanger | Header nails | Joist nails | Per hanger |
|---|---|---|---|---|
| 2x4 | LUS24 | 4 | 2 | 6 |
| 2x6 | LUS26 | 4 | 4 | 8 |
| 2x8 | LUS28 | 6 | 4 | 10 |
| 2x10 | LUS210 | 8 | 4 | 12 |
Hangers and nails for common ledgers
2x8 joists 16 in on center, hung at the ledger only.
| Ledger | Joists | Hangers | Nails |
|---|---|---|---|
| 10 ft | 9 | 7 | 70 |
| 12 ft | 10 | 8 | 80 |
| 16 ft | 13 | 11 | 110 |
| 20 ft | 16 | 14 | 140 |
| 24 ft | 19 | 17 | 170 |
Getting hangers right
Fill every hole the schedule calls for, with the fastener it names: the load tables assume them. Seat the joist tight to the bottom of the hanger, and use hangers and nails with a coating rated for treated lumber. Where the joists also hang from a flush beam, count both ends. Plan the ledger with the deck ledger calculator and the joists with the deck joist calculator.
Get the Smart Decking Calculator app for Android
Estimate decks on the go, save projects, and share them with contractors.
Building something else? Try our sister calculators
Smart Fencing Calculator
Estimate fence cost by material and linear footage.
Smart Roofing Calculator
Free roof replacement cost estimates by material.
Smart Drywall Calculator
Android app — drywall sheets, mud, and tape estimates.
Smart Fencing Calculator
Android app — fence cost estimates on the go.
Frequently asked questions
- How many joist hangers do I need?
- One for each joist end that butts into a ledger or flush beam. A 16 ft ledger with joists 16 in on center has 13 joists; the two end joists are usually the rim, so 11 hangers. If the joists also hang from a flush beam at the far end, double it.
- What nails go in joist hangers?
- The nail the hanger maker specifies — for Simpson's LUS hangers that is a 0.148 × 3 in (10d common) nail, or their SD connector screws. Don't use drywall screws, deck screws or roofing nails: they aren't rated for the shear load.
- How many nails go in a joist hanger?
- Every hole the schedule lists. Simpson's LUS26 (2x6) takes 4 header nails and 4 joist nails; LUS28 (2x8) 6 and 4; LUS210 (2x10) 8 and 4; LUS24 (2x4) 4 and 2.
- Do joist hangers count as blocking?
- They can provide the lateral restraint at the joist end. The 2021 IRC (R507.6.2) accepts joist hangers or blocking for end restraint where their depth is at least 60 percent of the joist depth.
- What size joist hanger for a 2x8?
- A hanger made for a single 2x8 — in Simpson's face-mount line, the LUS28. Doubled joists need a double hanger sized for 3 in of lumber, such as the LUS28-2.
