If you’re in the market for a new roof, you’ve no doubt stumbled across advertisements that say “50% off!” or “Zero dollars down!” Almost every roofer advertises in this way because it’s effective. But it can be somewhat misleading. Claims like these can make you unsure of what to believe.

One important thing to keep in mind when looking at prices for a new roof is that you get what you pay for. At the end of the day, roofing materials cost money, and the labor to install them costs money. While prices will vary somewhat based on a number of factors, all will reflect the cost of materials and labor. When a price is significantly lower than the rest, or when a deal sounds too good to be true, that’s because it is. Here are some tips for making sure the cost of your new roof measures up.

The size and scope of the project

Roofing costs are calculated by a number of factors. One of the most obvious ones is the size of your roof. The larger the roof, the more materials you’ll need to cover it. Roofing materials are measured in “squares” where one square represents a 10 foot by 10 foot section (or 100 square feet). A little investigative work can tell you about how much you can expect to spend on a given roofing material based on the size of your roof. If your roof is particularly steep or has complex architectural features like odd shapes and angles, the price will probably be a little bit higher.

If a roofer is advertising a cost per square than is significantly lower than other roofers, there’s a good chance they’re using inferior materials or short cuts of some kind. You don’t want inferior roofing materials or inferior work because your roof is arguably the most important part of your home.

Get several roofing bids

It’s recommended that you get at least three roofing bids. Getting more than one is important because it gives each bid another one to compare it with. With each bid you’ll see an estimate of the size of your roof. Measuring the square footage of a roof is somewhat imprecise so don’t be surprised if there is a slight variance in measurements. Be wary of any roofers whose estimate is way off from other estimates, however.