Measuring the Roof

What’s the best way to measure a roof to find out how many square of shingles it is?


With a tape measure. It also helps to bring paper and pen or pencil to keep track of numbers.

The really good roofers can do all that from a computer. They hire a third party to measure the roof off arial images and satellites.

Works best for me to draw a diagram of the roof and lay it out flat. Been measuring 3-4 per day for a few weeks now.

L x W x 2 = sq. ft. if valleys add 1 sq. per. + 10% waste.
Dougger…what form of advertising do you use to get 3-4 a day to measure? I would love to have that kind of demand…and call volume

(L * W) = sq ft

So a 10’ x 10’ deck is 100sq ft which is 1sq

Where does the x2 come in?!

Everything is a triangle, square or trapizoid. L x W like everyone said.

I know alot of people use a 10% but i have not for years and am short maybe once in a great while.


x2 must be either a new BMW model or a pitch multiplier… :mrgreen:

if it is the second one, I do not know how jwoolf is still roofing :slight_smile:

x2…Measure one side…x2= entire roof…eh em What do you guys measure both sides that are the same ,and add,cause you can’t multiply?

Well usually two sides arent the same. If they are then I will multiply by two. I usually measure around 10 a week and what a waste of time it can be because usually only 2 or 3 decide to go with us. Make sure you remember to add in the amount of starter you need as well as cap. The first time i ever measured a roof I completly forgot to do that and boy did I feel like an idiot.

[quote=“jwoolfsroofing”]L x W x 2 = sq. ft. if valleys add 1 sq. per. + 10% waste.
Dougger…what form of advertising do you use to get 3-4 a day to measure? I would love to have that kind of demand…and call volume[/quote]

Word of mouth.

Ed should post soon as I know he’s got measuring down to a science.

If the roof pitches are the same I measure as if it were flat on each side. If the roof has different pitches triangle each section.

Gable roofs add 10%
Hip roofs add 15% (for insurance jobs).

In all reality if say a roof is 28.45sq off for example I usually order 30sq and usually have a bundle or two left over.

My guys don’t waste much with the Landmarks.

I only responded to this one because my name was called out.

I always measure everything on the roof.

From Eave corner to the next end or change in direction.

For hip roofs and valleys, I add 1 foot in that hip or valley direction

For valley waste, every 11’5" equals one bundle of lost waste shingles, but that is already accounted for in the one foot from each side direction adjusted measurement.

There is no such thing as inches.

16’7" up on a rake edge for the rafter length means 17 foot even.

I calculate every 80 feet of eave edge and rake edge as one bundle, or 1/3rd square for bidding purposes. F’ the insurance companies that do not pay for starters and bleeders being torn off. Stop at that point and ask them to send out their Starter and Bleeder Strip Shingle Removal crew for the Free amount that they have accounted for in their pricing. Plus, tell them that your crew will be on the clock at the $ 75.00 per man hour rate until the insurance company removes those items.

Sorry about that off topic tangent.

I use every 30 feet of either Hip or Ridge as another bundle, or 1/3rd square.

I eyeball the entire job after all of those calculations and add on a minimum of 2/3 square on an easy no waste job and 1 square to 1 2/3 square more for a medium waste job.

I will never ever be short on one job, but I may have 3 squares left over to return, but I also always leave one partial bundle and one full bundle with the home owner for future color matching needs for unknown potential repairs from wind or animal damage, but the home owner is paying for those extra bundles in the proposal calculations.


Here in michigan Ed we cant be heavy 3 squares, or we lose the job. I usually am short when i miss add when im in a hurry. I was just taught to be close. Everyone will meausre a little different. I measure everythin on the roof also myself. Unless i cant walk it then i might be 3 square heavy.

No matter what I do when I measure a complex hip roof with varying elevations for different ridge lines, it never comes out the same.

I’ve tried all sorts of different suggestions and even tried the footprint and pitch factor version, but I usually am too heavy on the total, but I would rather be an average of 1 square too much than 1/3 square too short.


I have been in this business over 20yrs and I believe ed hasthe best way of measuring roofs as it is the one I use.

Being over on materials is always better than being under. So far this year don’t think I have been short on any roofs and the most over has been 5 bundles.

On some jobs when the roof is done have a partial of everything left.

Thanks for posting Ed! Sorry if you felt forced into giving up some of your trade secrets!!!

Luckily insurance pays so much for waste that it covers the starters and ridge if it’s a three tab roof.

Here is an example of a rather large hip roof that an adjuster figured recently
50.88 off Horizon Shangles
58.67 on
386.4 ft of ridge that they paid.

I ordered 52 squares and had five bundles left over. More than likely the adjuster figured a little more than what the roof really was. Sad to say this was the only insurance job I have ever done without measuring the roof. What I did do was measure the ridge, step flashing, drip edge, valley, and count all the vents. It was a very cut up 8/12 10/12 hip roof with a tarret. Insurance paid $23,500 for it.

What I do is load up the extra materials into the pick up and give them to the boom truck driver on the next job. Never give them back felt or w%i those get used on the next job.

You know me better than that Dougger,

If I have something that can help, I share it.

There are lots of ways to measure and everyone chooses what fits.