Roof Measuring Formula

Use the following formula which also describes a right triangle.

Roof measuring formula.

Here are the equations you may use to solve for the length of the slope and the rafter. Get unlimited measurements high definition imagery and free support. Our roof calculator uses base length and base width to find the estimated area. Don t use this as your only method of measuring.

For instance a 7 12 roof pitch means that the roof rises 7 inches. Measure the length and width of each portion of the roof multiply length by width for each plane and then add the planes together for the total square footage. Rafter rise run this formula is from the pythagorean theorem. The next step is to measure the pitch also referred to as the roof slope of the roof deck.

You ll need to figure out the vertical distance also known as the rise over a 12 horizontal segment also known as the run. See the diagram. The roof area is simply 114x18x2 plus 30x18x2 giving 5184 square feet which is perfectly adequate for estimating materials. Record these values as roof rise over run with the vertical measurement listed first and the horizontal second.

Just use it as a starting point and you ll have a fairly basic idea of what you re dealing. Keep in mind that using google earth isn t going to give you a 100 percent accurate reading but it will give you a basic idea of the size of the roof for your calculations for the roofing materials. To calculate the size of the roof you need to measure the size of the roof as if it were flat account for roof pitch calculate square footage and finally determine how many squares of material are required for the roof the calculator above can handle all of this simply enter the length width and pitch and it will determine the size of the roof in squares. The base width is the distance from one corner of your roof to the other at its base on the short side of your house.

In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches. If you have a simple gable roof you ll only need to measure and sum up the 2 planes of the roof. This is only important for gable roofs as the calculator uses a specific formula to estimate roof run length of gable. Roof pitch is the measurement of a roof s vertical rise divided by its horizontal run.

You can also calculate roof pitch even without using a roof slope calculator. Measure both the width gable side and the length eave gutter side. Area is defined as the expanse or measurement of a given surface and there are a few methods for measuring your roof s area. It is often compared to slope but is not exactly the same.

If your house has a hip roof then it does not matter which side is the length and which is the width for an accurate result.