A 10/12 roof pitch can also be expressed as 10 over 12 and when you're talking to a roofer, this is the most common way you'll hear it explained because it's easy to say in conversation.
A 10/12 roof pitch is steeper than average, so it is a little harder and more expensive to install. A benefit of this pitch is that it will shed water effectively without requiring larger gutters.
Another way to express a 10/12 pitch is "10 and 12."
In this pitch, the 10 represents your roof's rise and 12 represents the roof's run.
The roof's incline increases ten feet for every 12 feet of horizontal measurement.
What angle is a 10 over 12 pitch?
Roofs with a pitch of 10/12 are approximately 39.81 degrees, depending on how exact you'd like to be in your measurement.
Check out our roof angle chart for more examples of the exact angles (expressed in degrees) of common roof pitches.
Pictured above is a Boston roof replacement we completed last Winter on a one story home. The entire roof is a 10 over 12 pitch, which is one of the steeper residential pitches to re-roof. You need to be careful when walking a roof of this steepness.