With a 'three tab' shingle, you should (will?) have 33 sq. ft. per bundle, so you will need 10-11bundles.
If a 'designer' shingle is used, you should (will?) have 25 sq. ft. per bundle, so you will need 13-14 bundles.
You may need an extra bundle or two, depending on the shape of your roof & how many full size shingles must be cut to fit.
If you have to shingle the ridge of the roof, you should get 21 Lft. per bundle
Call or visit your local building supply store, ask for their 'Service Counter' or Project Desk' to verify the shingles ( colour, style, size & size per bundle ) that they have in stock or have access to.
Styles & sizes vary by geographic location.
There are 3 bundles in a square and you have 2 squares so 6 bundles.
3 bundles equal 100 sq feet, don't forget to factor in that the first row is doubled and then the roof cap
12
15 bundles
3
3
33
There are 3 bundles of conventional shingles to a square, so 3 X 27
3
21
3 bundles per square on average. So 3.5 square is 10 bundles.
6x6 is 36 square feet, so just over 1 bundle. 3 bundles in a square which is 100 square feet. When using the common '3 Tab' shingles, 3 bundles = 1 square. Various manufacturers make higher end shingles that are installed differently and require 4 bundles to equal 1 square.
Standard fiberglass shingles come 3 bundles to the square.
3
How many bundles of 3-Tab Shingles are needed to cover 80 square feet?
If your shingles say they cover 3 bundles to a square ( 10'x10' or 100 sq. ft) then one and a half. Some thicker, heavier shingles are 4 bundles to a square so you'd need 2.
20 year = 4 to a square. 30 year = 3 to a square. Most 20 year are also 3 bundles per square
9 bundles assuming std. 3 bundle/sq. shingles
Typically there are three (3) bundles per square (100 sq ft)