How To Measure A Roof
Getting accurate roof measurements can be difficult but with this roofing calculator, you’ll be well prepared to take measurements of any roof. Whether you’re a contractor looking to train a new employee or a homeowner looking to do some renovations, you’ll find this guide helpful for any roofing project. Use the step-by-step guide below to accurately measure your roof and estimate roofing costs.
Satellite Roof Measurements: Features of a Roof Report
- Accurate Roof Pitch Measurements
- Roof Measurements including Area, Rakes, Ridges, Hips and Valleys, and every edge is separately measured and identified.
- CAD style drawings with colored lines identifying every type of roof edge
- Online access to your Roof Reports for your Employees, Subs and Suppliers with no software to install
- Multiple image providers for over 98% coverage of the USA & Canada
- Also supports file formats such as XML, RXF, DXF/DWG AND WRL
MEASURING THE PITCH
- Use your measuring tape to measure 12 inches on your large level and make a mark.
- Place your ladder at the gable end and climb to the top of your roof.
- Place your level against the gable trim and flat against the house.
- Measure from the 12-inch mark on your level up to the bottom edge of your gable trim. This is your rise.
- Your roof’s pitch is written as “# in 12” (e.g., 4 inches = 4 in 12).
CALCULATING THE AREA
- Divide the roof pitch by 12 (e.g., 4 in 12 = 1/3).
- Square the result (1/3² = 1/9).
- Add 1 (1/9 + 1 = 10/9).
- Find the square root (√10/9 = 1.05).
- Measure house length and width (e.g., 40ft × 30ft = 1200 sq ft).
- Multiply area by pitch (1200 × 1.05 = 1260 sq ft).
- Add 10% for gable roof (1386 sq ft) or 17% for cottage roof (1474 sq ft).
Acreage Calculator – Measure the area of a plot of land
Start by entering an address or GPS coordinate. This places a marker for drawing the area on the map. Once finished, the calculator will display the area above the map.
How to use the Google Maps area calculator tool to measure a roof
Satellite images are at slight angles, causing errors when measuring pitched roofs. Click only on points at the same elevation—like roof corners—not the peak. For multi-level roofs, measure each section separately. This tool is an estimate and should not be your only measurement method.