Roof Pitch Chart

The chart gives every whole pitch from 1 in 12 to 24 in 12 as an angle in degrees, a slope in percent and a multiplier, with the hip or valley length for each foot of run.

Estimates for planning, not professional advice. Read the full notice.

Work it out for your own sizes

Work out your own pitch

Roof pitch chart

Each pitch as a rise in twelve with its angle in degrees, its slope in percent, its multiplier and the hip or valley length for each foot of run

PitchDegreesPercentMultiplierHip or valley per foot of run
1/12 4.76 degrees8.33 percent1.0031 ft 5 in
2/12 9.46 degrees16.67 percent1.0141 ft 5 1/16 in
3/12 14.04 degrees25 percent1.0311 ft 5 1/4 in
4/12 18.43 degrees33.33 percent1.0541 ft 5 7/16 in
5/12 22.62 degrees41.67 percent1.0831 ft 5 11/16 in
6/12 26.57 degrees50 percent1.1181 ft 6 in
7/12 30.26 degrees58.33 percent1.1581 ft 6 3/8 in
8/12 33.69 degrees66.67 percent1.2021 ft 6 3/4 in
9/12 36.87 degrees75 percent1.251 ft 7 3/16 in
10/12 39.81 degrees83.33 percent1.3021 ft 7 11/16 in
11/12 42.51 degrees91.67 percent1.3571 ft 8 1/4 in
12/12 45 degrees100 percent1.4141 ft 8 13/16 in
13/12 47.29 degrees108.33 percent1.4741 ft 9 3/8 in
14/12 49.4 degrees116.67 percent1.5371 ft 10 in
15/12 51.34 degrees125 percent1.6011 ft 10 5/8 in
16/12 53.13 degrees133.33 percent1.6671 ft 11 5/16 in
17/12 54.78 degrees141.67 percent1.7342 ft
18/12 56.31 degrees150 percent1.8032 ft 3/4 in
19/12 57.72 degrees158.33 percent1.8732 ft 1 1/2 in
20/12 59.04 degrees166.67 percent1.9442 ft 2 1/4 in
21/12 60.26 degrees175 percent2.0162 ft 3 in
22/12 61.39 degrees183.33 percent2.0882 ft 3 13/16 in
23/12 62.45 degrees191.67 percent2.1622 ft 4 9/16 in
24/12 63.43 degrees200 percent2.2362 ft 5 3/8 in

Estimate for planning, from what you entered and the product data shown. Check product labels and your supplier before you buy.

Hip and valley lengths are for two planes of the same pitch. The multiplier takes a flat area to the area of the sloped surface.

2021 IRC wording at these pitches

The pitches the 2021 IRC names for asphalt shingles and for the steeper-slope ice barrier distance, each with its section wording

Pitch2021 IRC value
2/12 2 in 12The 2021 IRC, section R905.2.2, says asphalt shingles are used only on slopes of 2 in 12 or greater, and from 2 in 12 up to 4 in 12 double underlayment application is required.
4/12 4 in 12The 2021 IRC, section R905.2.2, says asphalt shingles are used only on slopes of 2 in 12 or greater, and from 2 in 12 up to 4 in 12 double underlayment application is required.
8/12 8 in 12The 2021 IRC, section R905.1.2, says an ice barrier extends to a point not less than 24 inches inside the exterior wall line, and on slopes of 8 in 12 or more also not less than 36 inches along the slope from the eave edge.

Source: [1]

These are model-code values. A pitch is compared with them as within, outside or at the value; the code your area has adopted may differ.

Pitches that sit at a 2021 IRC value

  • 2/12: at the 2021 IRC value for asphalt shingles and the double-underlayment range, quoted below
  • 4/12: at the 2021 IRC value for the double-underlayment range, quoted below
  • 8/12: at the 2021 IRC value for steeper slopes, quoted below

Questions

What is a 4/12 roof pitch?

It is a roof that rises four inches for every twelve inches of run. The chart gives its angle, its percent and its multiplier in the row for that pitch, and the model-code wording at that pitch is quoted below the chart.

What is a 6/12 roof pitch?

It is a roof that rises six inches for every twelve inches of run. The row for that pitch gives the angle, the percent and the multiplier, all worked out by the engine from the rise.

Which pitches are common?

The chart lists every whole pitch in its range so you can find yours. It does not rank pitches; the model-code values the page quotes are the only comparisons it makes, and your building department decides what applies.

What is the multiplier for?

Multiply a flat area under a plane by the multiplier for its pitch to get the area of the sloped surface. The roofing calculator does this for every plane before it adds the planes together.

Calculate it for your project

Enter your own sizes to get the amount to buy or the layout figures, with the working shown and a page to print.

Turn your measurements into a pitch

Local codes and amendments differ; your building department decides.

Sources (1)
  1. 2021 IRC, Chapter 9 Roof Assemblies, R905.2.2 Slope, International Code Council, 2021 IRC. Code or government
    “Asphalt shingles shall be used only on roof slopes of 2 units vertical in 12 units horizontal (17-percent slope) or greater. For roof slopes from 2 units vertical in 12 units horizontal … up to 4 units vertical in 12 units horizontal (33-percent slope), double underlayment application is required…”
    “…in areas where there has been a history of ice forming along the eaves … as designated in Table R301.2 … not less than 24 inches (610 mm) inside the exterior wall line … slope equal to or greater than 8 units vertical in 12 … not less than 36 inches (914 mm)…”
    Checked November 12, 2026. Figures and codes change; verify with the source. Back to where this is used

These are summaries of what the sources say, not professional advice. Codes and product data change. Check with your building department and the product label about your own project.

Made with HoneyDoMath.com. Estimates for planning; check product labels and local codes before you buy or build.