Deck Material Calculator
Estimate joists, beams, decking, fasteners and footings for a deck frame.
Estimated material cost
$2,773
192 sq ft of deck, or $14 per square foot in material alone.
- Decking boards26 rows at 5.75 in per course
- 29 × 16 ft
- Joists2x10 at 16 in on center
- 13 × 12 ft
- Beam & rim lumber32 LF beam, 56 LF rim and ledger
- 88 LF
- Posts & footingsPosts land 8.0 ft apart
- 3
- Joist hangersOne per joist at the ledger
- 13
| Item | Quantity | Unit | Unit cost | Extended |
|---|---|---|---|---|
| Joists — 2x10 × 12.0 ft | 13 | pieces | $23.40 | $304 |
| Ledger, rim & end joists — 2x10 | 56 | linear ft | $1.95 | $109 |
| Beam — 2-ply 2x10 | 32 | linear ft | $1.95 | $62 |
| Composite / PVC — 16 ft boards | 29 | boards | $62.00 | $1,798 |
| Posts, bases & footings — 2.0 ft posts | 3 | each | $145.00 | $435 |
| Joist hangers | 13 | each | $1.65 | $21 |
| Hidden fastener clips | 390 | each | $0.11 | $43 |
| Material total | $14.44/sq ft | $2,773 |
2x10 at 16 in OC carries the 12.0 ft span
The IRC R507 table allows 14.0 ft for a 2x10 at 16 in on center in No. 2 treated southern pine. Other species and grades span less, so confirm the grade stamp on what you actually buy.
Joist spacing suits the decking product
Composite / PVC is normally rated to 16 in on center for a perpendicular layout. Composite and PVC boards drop to 12 in on center for a diagonal pattern, and most manufacturers void the warranty if the framing is wider than their instructions allow. This is the one decision you cannot retrofit after the frame is built — check the decking installation instructions before you set joists.
The ledger is where decks fail
Deck collapses begin at the ledger connection far more often than anywhere else. Nails are not acceptable. Use through-bolts or approved structural screws in the pattern given in IRC R507.9, flash the ledger properly, and never fasten to brick veneer or to a cantilevered rim joist. At 3.0 ft above grade this deck also needs a guard, and above 30 in a lateral load connection per R507.9.2 applies.
What this assumes
- Joist spans follow common pressure-treated southern pine values; verify against your local span tables.
- Composite decking generally requires 16 inch joist spacing, or 12 inch for diagonal patterns.
- Footing count assumes a standard beam-and-post layout with posts at or under 8 foot centers.
Important
Decks require a permit almost everywhere, and ledger attachment is the single most common cause of deck collapse. Follow the IRC prescriptive deck provisions in R507 or have the connection engineered.