Question 1

How many bundles of shingles do I need?

Accepted Answer

Multiply the building footprint by the roof pitch multiplier (√(12²+pitch²)/12), add a waste percentage of 10–15%, divide by 100 to get roofing squares, then multiply by 3 bundles per square for 3-tab or architectural shingles at ~33 sq ft coverage per bundle. MatCalc360's Roofing Calculator does this instantly.

Question 2

How much concrete do I need for a slab?

Accepted Answer

Multiply length × width × depth in feet, divide by 27 to get cubic yards, and add 5–10% waste. For 80 lb bags, roughly 45 bags per cubic yard. MatCalc360's Concrete Calculator returns cubic yards plus both 60 lb and 80 lb bag counts.

Question 3

What is the roof pitch multiplier?

Accepted Answer

The roof pitch multiplier converts flat footprint area to sloped roof surface area. Formula: √(144 + pitch²) / 12. A 6/12 pitch has a multiplier of about 1.118.

Question 4

Can I estimate my roof from a photo?

Accepted Answer

Yes. MatCalc360's Homeowner mode uses AI vision to identify roof shape, ridges, valleys, hips and dormers from an uploaded photo, then combines that with your building's length × width to produce a material estimate.

Question 5

Does the calculator handle feet-inch math?

Accepted Answer

Yes. Enter 5'6" + 2'4" and MatCalc360 returns 7' 10" rounded to 1/16". Works for +, −, ×, ÷ with feet-inch inputs.

Dimensions	20 ft (6.10 m) × 10 ft (3.05 m) × 4 in
Concrete volume	2.47 cu yd (1.888 m³) (66.666667 ft³)
Waste factor	0%
60 lb bags	149
80 lb bags	112

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