Stair spec sheets
for every height.
Every deck height from 18" to 60" in 2" steps and every floor-to-floor rise from 66" to 144" in 6" steps. Each sheet compares the fewest legal risers with a gentler layout, gives the 2x12 board length and the hook-once tape marks, and checks the IRC and AWC DCA 6 limits. Ceiling heights convert at 12" of floor framing (2x12 joists plus a 3/4" subfloor).
Decks, porches and stoops 22 sheets
| Total rise | Option A risers | Treads · run | 2x12 board | Option B risers | Run (11" treads) |
|---|---|---|---|---|---|
| 18" | 3 × 6" | 2 · 20" (1' 8") | 8 ft | 4 × 4-1/2" | 33" |
| 20" | 3 × 6-11/16" | 2 · 20" (1' 8") | 8 ft | 4 × 5" | 33" |
| 22" | 3 × 7-5/16" | 2 · 20" (1' 8") | 8 ft | 4 × 5-1/2" | 33" |
| 24" | 4 × 6" | 3 · 30" (2' 6") | 8 ft | 5 × 4-13/16" | 44" |
| 26" | 4 × 6-1/2" | 3 · 30" (2' 6") | 8 ft | 5 × 5-3/16" | 44" |
| 28" | 4 × 7" | 3 · 30" (2' 6") | 8 ft | 5 × 5-5/8" | 44" |
| 30" | 4 × 7-1/2" | 3 · 30" (2' 6") | 8 ft | 5 × 6" | 44" |
| 32" | 5 × 6-3/8" | 4 · 40" (3' 4") | 8 ft | 6 × 5-5/16" | 55" |
| 34" | 5 × 6-13/16" | 4 · 40" (3' 4") | 8 ft | 6 × 5-11/16" | 55" |
| 36" | 5 × 7-3/16" | 4 · 40" (3' 4") | 8 ft | 6 × 6" | 55" |
| 38" | 5 × 7-5/8" | 4 · 40" (3' 4") | 8 ft | 6 × 6-5/16" | 55" |
| 40" | 6 × 6-11/16" | 5 · 50" (4' 2") | 8 ft | 7 × 5-11/16" | 66" |
| 42" | 6 × 7" | 5 · 50" (4' 2") | 8 ft | 7 × 6" | 66" |
| 44" | 6 × 7-5/16" | 5 · 50" (4' 2") | 8 ft | 7 × 6-5/16" | 66" |
| 46" | 6 × 7-11/16" | 5 · 50" (4' 2") | 8 ft | 7 × 6-9/16" | 66" |
| 48" | 7 × 6-7/8" | 6 · 60" (5' 0") | 8 ft | 8 × 6" | 77" |
| 50" | 7 × 7-1/8" | 6 · 60" (5' 0") | 8 ft | 8 × 6-1/4" | 77" |
| 52" | 7 × 7-7/16" | 6 · 60" (5' 0") | 8 ft | 8 × 6-1/2" | 77" |
| 54" | 7 × 7-11/16" | 6 · 60" (5' 0") | 8 ft | 8 × 6-3/4" | 77" |
| 56" | 8 × 7" | 7 · 70" (5' 10") | 8 ft | 9 × 6-1/4" | 88" |
| 58" | 8 × 7-1/4" | 7 · 70" (5' 10") | 8 ft | 9 × 6-7/16" | 88" |
| 60" | 8 × 7-1/2" | 7 · 70" (5' 10") | 8 ft | 9 × 6-11/16" | 88" |
Raised decks, basements and full storeys 14 sheets
| Total rise | Option A risers | Treads · run | 2x12 board | Option B risers | Run (11" treads) |
|---|---|---|---|---|---|
| 66" | 9 × 7-5/16" | 8 · 80" (6' 8") | 10 ft | 10 × 6-5/8" | 99" |
| 72" | 10 × 7-3/16" | 9 · 90" (7' 6") | 10 ft | 11 × 6-9/16" | 110" |
| 78" | 11 × 7-1/16" | 10 · 100" (8' 4") | 12 ft | 12 × 6-1/2" | 121" |
| 84" | 11 × 7-5/8" | 10 · 100" (8' 4") | 12 ft | 12 × 7" | 121" |
| 90" | 12 × 7-1/2" | 11 · 110" (9' 2") | 12 ft | 13 × 6-15/16" | 132" |
| 96" | 13 × 7-3/8" | 12 · 120" (10' 0") | 14 ft | 14 × 6-7/8" | 143" |
| 102" | 14 × 7-5/16" | 13 · 130" (10' 10") | 14 ft | 15 × 6-13/16" | 154" |
| 108" (8 ft ceiling) | 14 × 7-11/16" | 13 · 130" (10' 10") | 16 ft | 15 × 7-3/16" | 154" |
| 114" | 15 × 7-5/8" | 14 · 140" (11' 8") | 16 ft | 16 × 7-1/8" | 165" |
| 120" (9 ft ceiling) | 16 × 7-1/2" | 15 · 150" (12' 6") | 18 ft | 17 × 7-1/16" | 176" |
| 126" | 17 × 7-7/16" | 16 · 160" (13' 4") | 18 ft | 18 × 7" | 187" |
| 132" (10 ft ceiling) | 18 × 7-5/16" | 17 · 170" (14' 2") | 20 ft | 19 × 6-15/16" | 198" |
| 138" | 18 × 7-11/16" | 17 · 170" (14' 2") | 20 ft | 19 × 7-1/4" | 198" |
| 144" | 19 × 7-9/16" | 18 · 180" (15' 0") | 20 ft | 20 × 7-3/16" | 209" |