## How To Calculate Number Of Roofing Shingles

Fortunately, you dont have to make a haphazard shingle estimate when planning for your roofing project: your roof size and chosen shingle type will guide the purchase process.

Shingles are sold in prepackaged bundles, not individually. Roofing manufacturers take the guesswork out of how many bundles you need per squareits listed in the specifications of each shingle they make. The specs for any given shingle will tell you how many bundles make up a square, how many shingles are in a square, and even the approximate number of nails youll need per square.

Often, three bundles of prepackaged asphalt shingles make one square, as is the case with the Timberline® HDZ Shingles. That said, the number of bundles you need can vary depending on shingle design. For example, five bundles of architectural asphalt shingles with artisan-crafted shapes, such as the Grand Sequoia® Shingle, cover one square. Once you know the number of squares of material your roof needs, check the shingle manufacturer specifications so you get your hands on exactly what you need.

If youre still deciding on the perfect shingle for your roof, play around with the GAF VirtualRemodeler. The free online tool helps you envision how different shingle colors and styles would work with your homes style. Be sure to keep local building codes in mind as you weigh your shingle options..

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## What Are Roof Shingles

Roofing shingles are watertight and wind-resistant seals that protect the roof from environmental damage. They are individual roof coverings that overlap one another when placed on the roof.

Many shingle installations are placed on top of an underlayment material such as asphalt felt paper which prevents leaks from rain and snow. In addition to having a variety of styles, colors, and textures, roofing shingles vary in price. On average, most homeowners pay between $8,000 and $9,000 for shingle installation.

Depending on the location, the availability of design varies per state. The type of shingle is considered before construction because the roof pitch and construction method varies. You can choose almost any kind of shingle to match your homes roofing design and increase the aesthetic of your home.

## Calculate The Simple Roof Areas

On a simple hip or gable roof, multiplying the eave to ridge length by eave length will give the area to be multiplied by pitch factor. Ridge vent openings are best finished with coil rather than partial shingle. Using flat coil stock allows the ridge caps to lay flat and can also be formed with an extra water stop at the ridge opening.

Area for the roof in **Figure 3** is 1784 ft2 The blue dash line divides the roof into 2 rectangles. There is a small area calculated as 8/12 that is actually 4/12. On a small area such as this, it is better to err on the side of the higher pitch since it should not significantly affect the total.

**Pro Tip:** Pythagorean Theorem can be used to calculate the length of the valleys. A general rule of thumb is to add at least 12 lineal inches of valley material to be safe.

Figure 3. Calculating Simple Roof Areas

**Also Check: What Causes Black Streaks On Roof Shingles **

## Calculate The Square Footage Of Your Roof

Now that you thought about the slope and complexity of your roof, youre ready to learn how to calculate the square footage of your roof.

To get a rough estimate for your roofs square footage, youll use this equation:

For example, if you have an easy up and over, walkable gable roof and a house that measures 56 feet lengthwise and 28 feet widthwise, your calculation will look like this:

1,568â² =

x 1.3

**2,038 = square feet of roof area**

**Using this equation wont be 100% accurate, but knowing your roofs square footage is a great jumping-off point to learn how much youll have to invest in your replacement.**

## How To Measure A Roof For Shingles

August 28, 2019 By Taylor-Made Roofing

Whether youre re-roofing your home or purchasing shingles for a brand-new house, its important to understand that a successful roofing project often requires a significant investment of both time and money. As you begin shopping for materials, you might wonder how to measure a roof for shingles. After all, roofing materials vary greatly in cost and are priced per square foot. To determine the size of your roof, contact a professional roofer who can measure your roof and provide an estimate for the roofing project.

**Recommended Reading: How To Estimate A New Roof **

## Roofing: Calculate The Number Of Shingles

**Roofing** is a very important part of your house because it protects it from water. Without a watertight room water would be allowed to enter and stream down the walls in your house. Its essential that the roof is in the very best condition.

Pitched roofs are commonly weatherproofed by using shingles, and these are arranged so that they overlap one another. Its important that you have the right number of shingles on your roof, because if you have too few then it wont be waterproof. You will then need to go back to the store a second time to buy more. Ordering too many roofing shingles will waste money.

There are a number of calculations that you can use to work out exactly how many shingles you need to correctly cover your roof. These calculations arent scary because you dont need to worry about anything you learned in school.

**Step 1 Calculating the Square Footage**

The first thing that you will need to do is work out the size of your roof in square feet. This is very easy, as its simply a matter of measuring the length and height of the room. Multiply the length and height of the roof together to work out the number of square feet that you need to cover. Remember to work out the total square footage around the whole of your house. For a simple room this will be very easy. However for larger, more complicated shapes you will need to work slowly.

**Step 2 Working out Number of Squares**

**Step 3 Work out Number of Bundles**

**Read Also: How Much To Shingle A House**

## What Is A Square In Construction

A square is an **imperial unit of area** used specifically in the construction business in the US and Canada. It is equal to 100 square feet.

Typically, you can expect to **see squares in calculations connected with roofing**, and it’s also not uncommon to use it for siding materials, like wallpaper or drywall. The unit can come in handy in the case of larger construction endeavors.

**Read Also: What Is The Minimum Slope For A Roof **

## How Do You Calculate Roofing

Roof Measurements Measure each plane of your roof by length and width. Divide this number by 100 to determine how many squares you have in your roof area. Add 10 percent for any overage that might be needed when installing the shingles. Divide the total number by 3, and you will know how many bundles you need to purchase for your roofing project.

## Draw A Quick Diagram Of The Property

The first thing to do when measuring a roof from the ground is to draw a quick diagram of the property. This ensures you wont accidentally miss a section and leave something out of your calculations. Plus, it gives you a place to record your measurements as you go along.

*Image credit: Rox Roofing*

Since youre working from the ground instead of up on the roof, its ok for this to just be a rough sketch of the overall shape of the house. Just make sure to label your diagram with basic reference points like front, back, left, and right. This helps to make sure that you record the measurements in the right place.

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## How To Measure Your Roof Area From The Ground

A more accurate way to calculate the area of the roof than using Google Earth is to get outside to **estimate the roof pitch** and the **base area** of the property. Using these two figures, we can get a good idea of the shingle roofs square footage and estimate your asphalt shingles needs and costs. This DIY technique can be helpful, especially if you are not comfortable getting on your roof, or if you have limited access to it.

Ground measures only work well for a gabled roof, since there are usually just two main rectangular pitches to calculate area for. For more complex roof shapes, like hip roofs, youll need to work with a roofer or measure from on top of the roof itself to calculate its total area.

## How To Calculate Your Roof Area

Knowing how to calculate your roof area can be a beneficial first step in estimating the cost of a new metal roof. In roofing we call the calculation of roofing materials needed a take-off.

A good roofing contractor will take the time make sure that the take-off is accurate. Proper measurements and attention to roof details ensure that material shortages are avoided and prevent overages .

**Recommended Reading: How To Get Rid Of Roof Stains **

## How To Calculate The Required Shingle Area

The calculated areas will help you estimate the material you will need, but to calculate the shingle needed for your beginner course, all you need to do is add linear feet to the eaves and divide the result by the length shingle. Multiply your total area by 1.05 to increase it by 5%. This will allow you to calculate the required area of the shingle and Add 10% to your total for trim allowances. Bituminous shingles are available in different sizes therefore, you should be sure what type of shingle you want to use before calculating. Here are some features of the shapes of the shingle.

## Determine Your Homes Area

Determine your homes base area by measuring the width and length. Find out the distance between the edge of one side of the eaves to the other edge on the same wall and note down the figure in feet. Use the measurement as the base width.

Do the same to the perpendicular wall to determine the base length. Then, multiply the structures base length and width to determine the roofs base area.

For example, if the base width is **30 feet** and the base length is** 60 feet**, youll multiply the two dimensions to find the roofs total base area of **1,800 square feet**.

**Recommended Reading: How Much To Patch A Roof **

## Calculating How Many Shingles Youll Need

**Convert the area into roofing squares, the measurement used for materials.**In roofing terms, a square is 100 square feet . Therefore, divide your total area by 100 to get the number of squares.XResearch source

**Determine the number of shingle bundles youll need by multiplying by 3.**Shingles typically come in a bundle thats large enough to cover 1/3 of a square. To figure out how many bundles youll need, multiply the number of squares by 3.XResearch source

**Figure out the amount of roofing felt youll need by dividing by 2 or 4.**Felt is what goes under the shingles. If youre buying 15-pound felt, 1 roll will be enough for 4 squares. If youre buying 30-pound felt, 1 roll will be enough for 2 squares. Divide your squares by one of these numbers to get the number of rolls youll need, depending on the thickness of felt you want.XResearch source

## How Many Shingles For Waste And Ridge Capping

As has been noted, you should add another fifteen percent to the total of your shingle estimate to cover any waste when having to cut shingles to fit, and also cover any damaged shingles that may come cracked or may crack when your helper drops them.

Ridge capping shingles are specifically formed to fit the ridge of the roof. While some people advocate using regular shingles on the ridge cap, many types will crack when you try to bend them over the ridge. Ridge capping shingles are not only formed to fit the ridge bend but they are also thicker than the other shingles to add protection for the roof and the rest of the shingles. Its much better to get ridge cap shingles for peace of mind and good protection.

To figure out how many ridge capping shingles youll need, measure the hips and ridges. Ridge capping shingles are usually one-foot square and are installed with an overlap so that the exposed part is five inches long for each. Figuring the number of ridge cap shingles can be done in more than one way. One way is to multiply the total ridge length by twelve, then divide it by five. If you have any doubts, bring your measurements with you to your supplier and hell help you figure it out.

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## Final Thoughts On Measuring Your Roof

If youre looking for a simple ballpark estimate of your roofing materials needs, Google Earth really does a great job of quickly allowing you to measure the square footage youll need to cover. While its technology sure is surreal, it has drawbacks in its ability to precisely measure distances represented in 3D. Therefore, it can be helpful to gauge estimates of your materials costs by measuring from the ground and on top of your structure. As always, if youre feeling confused, dont hesitate to get in touch with a local roofing contractor to help you out. Many will provide estimates for free. Simply ask how many squares of material they estimate youll need, and compare that to the results you got from using any of the methods we outlined above.

## Calculate The Area And Square Footage Of The Roof

Once you have all your measurements, youre going to use them to calculate the area. If you remember from math class, the area of a rectangle is found by multiplying the length of a space by the width of a space. This gives you the total area in between the sides.

*Image credit: nachi.org*

In the case of a roof, lets say the house has two long sides that measure 40 feet , two short sides that measure 20 feet , and a 10 x 10 addition on the back. To find the area of each space, you would do the following calculations:

40 feet x 20 feet = 800 square feet10 feet x 10 feet = 100 square feet

Then you would add the separate spaces together to get the total area or square footage of the roof. In this case, it would be:

800 square feet + 100 square feet = 900 square feet

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## Is 7/16 Osb Ok For The Shed Roof

**There is no problem using 7/16-inch OSB for the shed roof, as long as you use the right fasteners. First, the OSB must be laid on a nail bed that is made so that its parallel to the shed floor and not perpendicular. **

It also needs to be laid at an angle with respect to the horizontal. And finally, all nails must be driven at least 3 inches into each piece of plywood for proper adhesion.

## How Many Bundles Of Shingles Will You Need

The average bundle of shingles covers 33.3 ft2, so **three bundles of shingles are needed per square**. Asphalt shingles range in price from about $25 per bundle for a standard 3-tab style to around $50-$75 or more for an upgraded architectural style.

Since transportation is a major cost factor, expect prices to vary by location. A typical bundle of shingles weighs about 75 pounds, while some premium products can weigh over 100 pounds per bundle, so consider delivery of materials.

**Read Also: How Much Do Erie Metal Roofs Cost **

## How To Measure A Roof For Shingles From The Ground

Remember when your high school algebra teacher said you needed to know how to calculate slope. He may have been thinking about measuring the square footage of a roof.

This method allows you to calculate roof slope and determine the roof area while keeping both feet firmly on the ground.

Begin by measuring the distance from the edge of the eave to the point at which you can barely see the slope of the roof. This works best if you can attach the tape measure to the eve, then walk to the appropriate place and take the measurement at eye level.

This measurement is the horizontal run of the roof. Now, stand under the gutter of the roof you are measuring the slope for and measure the distance from your eye to the roof overhang. This is the roof rise.

Divide the roof rise by the horizontal run to get your roof pitch. For example, if the rise is 60 inches and the run is 120 inches, youll have a roof pitch of 6/12.

As in the method described above, measure the length of the roof from the edge of one eave to the other and the width from one eave to the other. For example, a roof that measures 60 feet by 40 feet would be 2,400 square feet.

Next, use the table below to determine the slope factor. In our example, the 6/12 roof would have a slope factor of 1.118. In our above example, you would multiply 2,400 square feet times the slope factor to get the total square footage of 2,683 square feet.