ContractorHandbook

How Many Shingles for a 3,500 Square Foot House?

Roofing squares needed

43 squares

A 3,500 square foot footprint, 70 by 50, at a 6/12 pitch with ten percent waste.

It does not stop at a number.

When the figures look right, the roofing material list downloads as a real PDF with your business details on it, built inside your own browser. Nothing you type is uploaded anywhere.

12 in of runrise, inrafter linefootprintroof surfacefootprint x slope multiplier / 100 = squares
A roof is always bigger than the house under it, and how much bigger is right angle geometry rather than an allowance. Square the rise, add 144, take the root, divide by 12, and that multiplier turns a footprint into real surface area before any waste is added.

How that number is worked out

These are the figures this page was built with and every line the calculator produces from them. Change anything above and all of it moves.

  • Building length70 ft
  • Building width50 ft
  • Roof pitch, rise per 12 in6 /12
  • Waste allowance10 %
  • Ridge length, 0 if unknown70 ft

Roofing squares needed43 squares

Footprint area3,500 sq ft
Slope multiplier at 6/121.12 x
Actual roof surface3,913 sq ft
Squares before waste39.1
Squares with 10% waste43order to this number

The material list this produces

Shingles, bundles (3 per square)130
Synthetic underlayment, rolls (10 sq each)5
Starter strip, linear ft276
Ridge cap, linear ft70
Drip edge, linear ft240
Roofing nails, lb95

Roof pitch compared

Pitch is the number most people guess at, and it is worth more shingles than any other input. Same house, five pitches.

Roof pitchRoofing squares needed
4/1240.6 squares
6/1243 squares
8/1246.3 squares
10/1250.1 squares
12/1254.4 squares

What else matters here

Thirty five hundred square feet of footprint at 6/12 is 3,913 square feet of roof, forty three squares with waste, a hundred and thirty bundles.

What comes off is as much of a logistics problem as what goes on. A square of architectural shingles weighs roughly 230 to 250 pounds, so one layer over thirty nine squares of roof is close to five tons of debris, and a second layer doubles it.

Dumpsters are rated by volume and this is a weight problem, so ask the hauler for a roofing rate rather than a general construction one and tell them the square count and the number of layers. A twenty yard container is a common size for a roof this big with one layer. Put plywood under the wheels on an asphalt drive, tarp the ground around the house before anything comes off, and agree who does the magnet sweep, because a roof tear off drops thousands of nails into a lawn.

What this calculator assumes

  • Footprint times the slope multiplier gives the actual roof surface. A 6/12 roof is 11.8 percent larger than the ground it covers, which is the number most people forget.
  • Three bundles per square is standard for both three tab and architectural shingles. Check your brand, a few premium lines run four.
  • Synthetic underlayment is figured at 10 squares per roll, starter and ridge cap at one linear foot per foot.

Questions people ask

How many bundles of shingles for a 3,500 sq ft house?

About 130 bundles at a 6/12 pitch with ten percent waste, which is 43 squares.

How much does a square of shingles weigh?

Roughly 230 to 250 pounds for architectural shingles, a little less for three tab. A single layer on a roof this size is close to five tons of tear off.

What size dumpster do I need for a roof tear off?

Give the hauler the square count and the number of layers and ask for a roofing rate, because it is a weight problem rather than a volume one. Twenty yards suits a large single layer roof.

Different numbers?

The roofing calculator takes any dimensions you like and hands back the same list.

Other common sizes