Enter parameters

Roof size:

sq. feet


x feet

Roof Pitch:

Choose material:


Roof area:
Number of squares:
Installation cost:

While the average lifespan for a typical roof can be 15-20 years, a long, hard winter or a particularly intense storm can cause lasting damage to a roof. Over time, that damage could really add up. As a result, you might need to calculate an estimate of how much it will cost to replace your old roof with a new one.

There are several factors to keep in mind for any estimate: the materials used for the shingles or seam panels, the surface area of the roof (with a measurement typically in squares), and any special features related to the complexity of the roof itself. In addition, details about your unique geography could play a role in the final cost of the project (e.g. if you live in the Northeast or some other region that gets a lot of winter storms).

The first step in a free roofing estimate is measuring the roof dimensions. You will need to express this size in terms of square feet. Keep in mind that the average size of a roof is 1,700 square feet, so your total will likely be 10% higher or lower than this figure. Check that your footage measurements are within this range so you can start off on the right foot.

Next, you will need to use a roofing materials calculator. Simply input the surface area of the roof, choose from one of the available options, and you will get your first roofing estimate. With an online roofing calculator, you will usually be able to drill down a bit deeper in order to see a fine-grained cost breakout on a sq ft basis.

But keep in mind that materials typically only account for 40% of the total cost of square roofing. The other 60% is labor. In the roofing trade, this is known as the installation cost, and it can vary widely depending on the type of replacement roof that you are getting. With an online calculator, you can see the various options for your roof and how they impact the final labor cost.

The best part of a roofing calculator is that it offers a free insight into the total cost of the replacement roof project on a sq ft basis. As you begin to calculate various costs, you will see that the cost is a result of the interplay of many different variables, including roof area (in terms of footage), measurement of any roof extras (like chimneys or skylights), and the dimensions of your roof.

Calculated quickly on a per foot basis, you can see that a bigger roof will almost always lead to a higher cost. However, there is not a direct 1:1 correlation between surface area and the total cost of the project, as expressed in dollars. Dimensions matter, as do the total amount of feet. This is especially true with shingle roofs (both metal and asphalt). Often, you can get discounts for using certain types of metal or asphalt, so always make sure that you check out these options when running all the numbers. For example, a steel roof will typically cost less than an aluminum roof.