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20/12 roof pitch in degrees

A 20-in-12 roof — 20 inches of rise for every 12 inches of run — as an angle, a percent grade, a slope ratio, and the rafter length it adds per foot of run.

20/12 pitch =

=59.04°

Angle

59.04°

Percent grade

166.6667%

Slope ratio

1.666667

Rafter / ft of run

1' 11-5/16"

What it means on the roof

Set a speed square to 59.04° for the plumb and seat cuts. Every foot of horizontal run adds 1' 11-5/16" of common-rafter length, so a run of 10 ft makes a rafter about ten times that. The percent grade (166.6667%) is the same slope a road sign or a laser level reads.

Nearby pitches

Pitches around 20/12

Pitch	Angle	Grade	Rafter / ft run
17/12	54.78°	141.6667%	1' 8-13/16"
18/12	56.31°	150%	1' 9-5/8"
19/12	57.72°	158.3333%	1' 10-1/2"
20/12	59.04°	166.6667%	1' 11-5/16"
21/12	60.26°	175%	2' 0-3/16"
22/12	61.39°	183.3333%	2' 1-1/16"
23/12	62.45°	191.6667%	2' 1-15/16"

All roof pitches Open the calculator

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