Method Two – Guess-timating roof pitch off the ground: While not as precise, the second method allows for a quick calculation, when ladder is not available, or when you need to get/provide a quick roofing price quote / estimate or quickly estimate roof size. Second method is more of a guesstimating way of getting a quick idea of the approximate roof pitch, while standing on the ground. First method of calculating roof pitch involves climbing up on the roof, or at least the roof edge and actually measuring the roof pitch using a carpenter’s level and a tape measure. There are two distinctly different methods of calculation the roof pitch – one is more accurate, while the other is faster and easier. For example, if you measured 7 inches, the roof’s ratio will be 7:12. The number you measured with the tape is the roof’s rise - the amount the roof’s height rises over 12 horizontal inches. If you decide to measure from the level down, you must add the length of the tape measure unit itself into the measurement. It is much easier to put the end of the tape on the roof and hold your hand up. Make sure you rotate the tape so it is perpendicular to the level. Hold the level parallel to the ground and measure the distance from the roof’s surface to the level’s 12-inch mark. Measure the rise with the tape measure.Pivot it up or down until the horizontal vial’s bubble is between the two lines. Using the level’s corner as your pivot point, hold the it parallel with the ground. While holding the tape measure with one hand, pick up the level with the other and place its bottom corner on the roof. Use your level to measure the roof run.Pull out your tape measure about 1 foot or so.Many levels are equipped with a ruler on the side, but marking it will allow it to be more visible. Nevertheless, our roof pitch calculator provides instant conversion from roof pitch to degrees and backwards, when you use it to calculate roof pitch. However, it is often difficult and unnecessary way to estimate a roof slope, while using roof pitch is simpler, faster, and often – more accurate. The roof can also be measures in degrees.

Calculating roof pitch using level and measuring tape:

How to calculate total rise of roof