6/12 Roof Pitch: Angle, Multiplier and What It Means
Angle
26.6 degrees
6 inches of rise for every 12 inches of run, over a 1,200 square foot footprint.
How that number is worked out
These are the figures this page was built with and every line the calculator produces from them. Change anything above and all of it moves.
- Rise6 in per 12 in run
- Footprint area, 0 to skip1200 sq ft
Slope multiplier1.12 x footprint
| Pitch | 6/12 |
|---|---|
| Slope multiplier | 1.12 xmultiply footprint by this |
| Angle | 26.6 degrees |
| Grade | 50% |
| Rafter length per 12 ft of run | 13.42 ft |
| Roof surface for 1,200 sq ft footprint | 1,342 sq ft |
| That is | 13.4 squares |
Pitch compared
The whole table, so you do not have to come back for the next one.
| Pitch | Slope multiplier | Angle | Grade |
|---|---|---|---|
| 2/12 | 1.01 x footprint | 9.5 degrees | 16.7% |
| 3/12 | 1.03 x footprint | 14 degrees | 25% |
| 4/12 | 1.05 x footprint | 18.4 degrees | 33.3% |
| 5/12 | 1.08 x footprint | 22.6 degrees | 41.7% |
| 6/12 | 1.12 x footprint | 26.6 degrees | 50% |
| 7/12 | 1.16 x footprint | 30.3 degrees | 58.3% |
| 8/12 | 1.2 x footprint | 33.7 degrees | 66.7% |
| 9/12 | 1.25 x footprint | 36.9 degrees | 75% |
| 10/12 | 1.3 x footprint | 39.8 degrees | 83.3% |
| 12/12 | 1.41 x footprint | 45 degrees | 100% |
What else matters here
A 6/12 pitch is 26.6 degrees and an exact 50 percent grade, which is the reason it comes up so often: the rise is half the run and the arithmetic is clean. It is the upper end of what most people will walk without fall protection and the lower end of what looks steep from the street.
The multiplier is 1.12, so a 1,200 square foot footprint is 1,342 square feet of roof, 13.4 squares. Twelve percent is a real number. Ordering off the footprint on a 6/12 house leaves you a square and a half short, which on a Saturday is the whole afternoon.
Six over twelve is also the point where attic space starts to be worth something. A 6/12 over a 28 foot wide house gives a ridge about seven feet above the ceiling joists, which is enough room to stand in the middle even if the edges are useless.
What this calculator assumes
- Pitch is written as rise over a 12 inch run. A 6/12 roof climbs 6 inches for every 12 inches across.
- The slope multiplier converts flat footprint area into real roof surface. It is the number that decides whether you order enough shingles.
- Below 2/12, shingles are not rated. Below 4/12, most manufacturers require a double underlayment. Over 8/12 you are on roof jacks and the labor price changes.
Questions people ask
What is a 6/12 pitch in degrees?
26.6 degrees, which is exactly a 50 percent grade.
Is a 6/12 roof steep?
It is on the edge. Most roofers will walk a dry 6/12 but will set jacks for a full day on one, and some regions price 6/12 and above as steep slope work.
What is the slope multiplier for?
Multiply the flat footprint of the building by it to get the real surface area of the roof. A roof plan gives you the footprint, and the multiplier turns it into the area you actually have to cover.
The roof pitch calculator takes any dimensions you like and hands back the same list.