What Roof Pitch Do I Have?

You can estimate your roof pitch by measuring the rise over a 12 inch run inside your attic using a level and tape measure, or by eyeballing it from the ground compared to reference photos, though that's much less accurate. For an exact pitch, and to know what it means for material options or cost, a roofer can measure it precisely during an inspection.

What roof pitch actually means

Roof pitch describes how steep a roof is, expressed as a ratio like 4:12, meaning the roof rises 4 inches for every 12 inches of horizontal run. A higher first number means a steeper roof.

Measuring pitch from your attic

If you have attic access, this is the most reliable DIY method. Hold a level horizontally against a roof rafter, measure exactly 12 inches out from where it touches the rafter, then measure straight up or down to the rafter at that 12 inch mark. That vertical measurement in inches is your rise, and your pitch is that number over 12.

Estimating from the ground

It's much harder to judge accurately from the ground, but as a rough guide, roofs that look noticeably steep are often in the 6:12 to 9:12 range, while flatter looking roofs common on ranch style homes are often 3:12 to 4:12. This is only a rough guess, not something to rely on for material decisions.

Why pitch matters

• Some materials, like standing seam metal, have minimum pitch requirements
• Steeper roofs generally cost more to work on due to safety requirements
• Pitch affects how quickly water sheds and how ventilation is planned
• Low slope sections sometimes need different underlayment or materials than steep-slope areas