Roof Pitch Calculator

Roof Pitch Calculator is perfect for both homeowners planning renovation and builders. Simply enter your roof run and rise measurements, and we'll tell you roof angle, rafter length and roof pitch.

What is Roof Pitch?

The roof pitch, also known as roof slope or roof angle, refers to the steepness or incline of a roof. It is typically expressed as a ratio, a fraction, or in degrees, indicating the vertical rise in inches for every horizontal foot. For example, a roof with a 4:12 pitch rises 4 inches vertically for every 12 inches horizontally.

How to calculate rafter lenght?

Calculating rafter length is a straightforward process that can be done using the Pythagorean Theorem. Here's how:

Formula:

$\text{Rafter Length}=\sqrt{{\text{Rise}}^2+{\text{Run}}^2}$

For example, if the rise is 6 feet and the run is 8 feet:

$\text{Rafter Length}=\sqrt{{\text{6}}^2+{\text{8}}^{\mathrm{2 }}}$

Rafter Length  = 10 feet

How to calculate Roof Pitch (x:12)?

To calculate the Roof Pitch in the form of x:12 (where x represents the vertical rise in inches for every 12 inches of horizontal run), you can use the formula:

$\text{Roof Pitch (x:12)}=\frac{\text{Rise}}{\text{Run}}\times 12$

Let's say we have a roof where:

• The rise (vertical distance) is 6 inches.
• The run (horizontal distance) is 12 inches.

$\text{Roof Pitch (x:12)}=\frac{\text{6}}{\text{12}}\times 12$

Roof Pitch (x:12) = 0.5×12

Roof Pitch (x:12)=6

So, for this example, the Roof Pitch (x:12) is 6.

This means that for every 12 inches of horizontal distance (run), the roof rises 6 inches vertically (rise). In other words, it has a 6:12 pitch.

This pitch is often simplified to a ratio of 1:2, meaning for every 1 unit of horizontal distance, the roof rises 2 units vertically.

How to calculate roof pitch in degree?

To calculate the Roof Pitch in degrees using the rise and run of the roof, you can use trigonometric functions. Specifically, you can use the arctangent function (also known as the inverse tangent function) to find the angle of the roof pitch. Here's the formula:

$\text{Roof Pitch (Degrees)}=arctan\left(\frac{\text{Run}}{\text{Rise}}\right)\times \left(\frac{\pi }{180}\right)$

Let's go through an example to understand how to calculate the Roof Pitch in degrees using rise and run.

Suppose we have a roof where:

• The rise (vertical distance) is 6 inches.
• The run (horizontal distance) is 12 inches.

$\text{Roof Pitch (Degrees)}=arctan\left(\frac{\text{6}}{\text{12}}\right)\times \left(\frac{\pi }{180}\right)$

$\text{Roof Pitch (Degrees)}=arctan \left(0.5\right)\times \left(\frac{\pi }{180}\right)$

$\text{Roof Pitch (Degrees)}\approx {26.57}^{\circ }\times 57.296$

$\text{Roof Pitch (Degrees)}\approx {1524.004}^{\circ }$

So, for this example, the Roof Pitch (Degrees) is approximately 26.57 degree.

How to calculate Roof Pitch in percentage?

To calculate the Roof Pitch in percentage, you can express the ratio of the rise to the run as a percentage. The rise-to-run ratio represents the vertical rise for every unit of horizontal run.

Here's the formula to calculate the Roof Pitch in percentage:

$\text{Roof Pitch (\%)}=\left(\frac{\text{Rise}}{\text{Run}}\right)\times 100$

You multiply the ratio of the rise to the run by 100 to express it as a percentage.

For example, if the rise is 6 inches and the run is 12 inches:

$\text{Roof Pitch (\%)}=\left(\frac{\text{6}}{\text{12}}\right)\times 100$

$\text{Roof Pitch (\%)}=\text{0.5 }\times 100$

$\text{Roof Pitch (\%)}= \text{50 \%}$

So, the Roof Pitch in percentage for this example is 50%. This means that for every 12 inches of horizontal run, the roof rises 6 inches, representing 50% of the total distance.

FAQs

What is a 2/12 roof pitch?

A 2/12 roof pitch means that for every 12 horizontal units, the roof rises vertically by 2 units. This is a relatively low slope, indicating that the roof has a gentle incline.

What is the minimum pitch for a lean to roof?

The minimum pitch for a lean-to roof generally depends on the roofing material used and the climate. However, a common minimum pitch for a lean-to roof is around 1/4:12 (1/4 inch of rise per 12 inches of run) to 1:12 (1 inch of rise per 12 inches of run).

Best roof pitch for solar panels?

The absolute best roof pitch for solar panels depends on a few factors, but in general, a pitch between 30 and 40 degrees is ideal for maximizing year-round energy production.