ContractorHandbook

7/12 Roof Pitch: Angle, Multiplier and What It Means

Angle

30.3 degrees

7 inches of rise for every 12 inches of run, over a 1,200 square foot footprint.

angle12 in of runrise, inmultiplierroot of (rise squared + 144) / 12 = multipliersame number as a degree angle and as a percent grade
Pitch, angle, grade and slope multiplier are four ways of saying one thing, and a drawing is the fastest way to see that. Everything on the page comes out of the same triangle: 12 inches of run along the bottom, the rise up the side.

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.

  • Rise7 in per 12 in run
  • Footprint area, 0 to skip1200 sq ft

Slope multiplier1.16 x footprint

Pitch7/12
Slope multiplier1.16 xmultiply footprint by this
Angle30.3 degrees
Grade58.3%
Rafter length per 12 ft of run13.89 ft
Roof surface for 1,200 sq ft footprint1,389 sq ft
That is13.9 squares

Pitch compared

The whole table, so you do not have to come back for the next one.

PitchSlope multiplierAngleGrade
2/121.01 x footprint9.5 degrees16.7%
3/121.03 x footprint14 degrees25%
4/121.05 x footprint18.4 degrees33.3%
5/121.08 x footprint22.6 degrees41.7%
6/121.12 x footprint26.6 degrees50%
7/121.16 x footprint30.3 degrees58.3%
8/121.2 x footprint33.7 degrees66.7%
9/121.25 x footprint36.9 degrees75%
10/121.3 x footprint39.8 degrees83.3%
12/121.41 x footprint45 degrees100%

What else matters here

A 7/12 pitch is 30.3 degrees. This is past the comfortable line: material will slide if you set it down and let go, and a crew that stages a 7/12 properly with jacks and planks will work faster over a full day than one that tries to hold on.

The multiplier is 1.16, so a 1,200 square foot footprint becomes 1,389 square feet of roof, just under 14 squares. On a tear off, remember that the debris comes off the same 1,389 square feet, so the dumpster sizing moves with the pitch too.

Steeper roofs shed water, snow and debris better and generally last longer for it, since the covering spends less time wet. That is the trade against the extra material and the slower day.

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 7/12 in degrees?

30.3 degrees, which is a 58.3 percent grade.

Is 7/12 considered steep slope?

In most pricing conventions yes. Steep slope premiums usually start somewhere between 6/12 and 8/12 depending on the region and the contractor.

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.

Different numbers?

The roof pitch calculator takes any dimensions you like and hands back the same list.

Other common sizes