How to calculate how much a new roof will cost

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There are various factors that help determine how much a new roof will cost. From the kind of shingles you opt for to the pitch and size of your roof, it can at times be somewhat difficult to figure out the exact amount. Though one of the ways to know about the new roof prices will be to request a professional for an estimate, you can also use a roofing calculator to determine the cost.

What will a roofing calculator do?

Roofing calculators will help you find out the amount of roofing material that will be needed to cover your roof. Once you are aware of the amount you will be able to calculate the material costs, which forms a large part of the overall cost. Even if you will be hiring a professional, the roof prices calculator still will help you figure out a lot about the expenses.

How to use the calculator

Before you start using the calculator you need to be aware of your roof’s pitch, your roof’s square footage, and the cost of shingles per square. When you are collecting this information there are a few things you must keep in mind. Your roof’s pitch can be different in different areas like over porches, dormers, or additions. So, make sure you calculate the pitch of all these areas individually and then calculate their square footage. Once you have the individual square shingles required per area, add them, and then multiply it by the expenses of the shingles.

The square footage

Start by measuring each area of the roof individually in inches. Once you have the width and length of each section, multiply the two numbers together, and then divide the resultant number by 144. This helps you get the square footage of an area.


For calculating the pitch you require a measuring tape and a 12-inch level. Climb to the top side of your roof using a ladder. Place your level horizontally off of your roof’s highest part. Next, from the 12-inch mark on your level, you need to measure down to the roof. The number of inches measured by you is the pitch.

Calculating your roofing

You simply need to multiply the square footage by the amount of pitch the way it is mentioned below and you get your roof’s square footage –

    • Pitch 4 in 12 should be multiplied by 1.06
    • Pitch 5 in 12 should be multiplied by 1.08
    • Pitch 6 in 12 should be multiplied by 1.12
    • Pitch 7 in 12 should be multiplied by 1.16
    • Pitch 8 in 12 should be multiplied by 1.20
    • Pitch 9 in 12 should be multiplied by 1.25
    • Pitch 10 in 12 should be multiplied by 1.30
    • Pitch 11 by 12 should be multiplied by 1.36
    • Pitch 12 in 12 should be multiplied by 1.42

Each square of roofing is equal to 100 square feet. If you need to cover 800 square feet you require 8 squares. You now simply need to multiply the number of squares by the cost per square and get the material prices for the new roof.

Using a roofing calculator will help you calculate quite accurate new roof prices, so you won’t have to wait and find out the necessary roofing details and material costs beforehand and can accurately start calculating immediately in order to get your estimates.  If you follow the instructions outlined above, you’ll definitely have an accurate depiction of what your new roof will cost.