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Roofing & Framing

Roofing Materials Calculator (Shingles & Squares)

This roofing calculator estimates squares, shingle bundles and underlayment from your footprint and pitch; our roof replacement guide covers materials and costs. Roofing is ordered in squares — 100 square feet of roof surface. Measure the footprint of the roof (including overhangs) from the ground, enter the pitch, and this calculator converts it to sloped area, squares, shingle bundles, underlayment and drip edge. For pricing, use the roof replacement cost calculator.

Results from this roofing calculator are planning estimates; confirm quantities and prices with your supplier or contractor before you order.

Enter your project

ft
in
m
ft
in
m
/12

Use the roof pitch calculator if unsure.

%

Typical 10% for simple gables, 15% or more for hips and valleys.

Most architectural asphalt shingles: 3. Check the wrapper.

sq ft

Felt rolls often ~400 sq ft; synthetic rolls ~1,000 sq ft.

Results

Your results will appear here

Enter your measurements and press Calculate. Defaults show a typical example.

How to use the roofing materials calculator

  1. Measure the outside dimensions of the roof footprint, including overhangs.
  2. Enter the pitch (x/12).
  3. Use 10% waste for a simple gable and 15% or more for hips, valleys and dormers.
  4. Check bundles per square and underlayment coverage on the products you plan to buy.

Formula

Roof area = footprint × √(1 + (pitch ÷ 12)²). Squares = roof area × (1 + waste) ÷ 100. Bundles = squares × bundles per square. This works for gable and hip roofs of a single pitch; add ridge-cap, starter strip and valley material separately.

Worked example

A 42 × 30 ft footprint at 6/12: 1,260 × 1.118 = 1,409 sq ft of roof. With 10% waste that is 15.5 squares → 47 bundles of 3-bundle-per-square shingles.

Tips for using the roofing materials calculator

  • Measure the footprint including overhangs; eaves and rakes add real roof area.
  • Add 10% waste for simple gable roofs and 15% or more for hips, valleys and dormers.
  • Order starter strip and ridge cap separately; they are not included in shingle bundle counts.
Roofer kneeling on a pitched roof fastening dark asphalt shingles with a nail gun

Roofing Materials Calculator FAQs

How many bundles of shingles are in a square?

Most asphalt shingles are packaged three bundles per square (100 sq ft), but some heavy designer shingles use four or five. The wrapper states it.

How many square feet does a bundle of shingles cover?

With three bundles per square, one bundle covers about 33.3 sq ft.

Does the calculator include ridge cap and starter?

No. Order ridge cap by linear foot of ridge and hip, and starter strip by linear foot of eave and rake, per the manufacturer.

Estimate before you call a contractor

Run the numbers with our free calculators so you can compare bids with confidence.

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