How To Find The Right Size Gutters for Your Home!

Buying new gutters is something you might want to consider. There are a few things to keep in mind when making your choice. Gutter size is one of them. The typical American home has gutters that are 5 or 6 inches wide, which are ideal for directing rainwater from the roof to the downspouts.

If you live in a home with a large or small number of slopes or if you have a variety of roofing materials, the size of the gutter will also vary in size. Your average 5-inch gutter may not be able to keep up with fast-moving water in some homes with steep slopes. If you need help figuring out what size gutters to get, we’re here to help you figure that out.

Understanding Your Gutters and Downspouts Functions

In order to keep rainwater away from your house, your gutters must do their primary task of water diversion. During strong rainstorms, water streaming from the roof can cause a variety of issues without the use of these devices. If you don’t have gutters, water will collect around your home’s foundation, which can lead to serious and expensive damage. In order to keep your property safe, here are some reasons why gutters and downspouts are essential for your home. 

Reason #1: Avoid Your Basement From Flooding

Because of the weight of all that rainwater dripping from your roof, your home’s basement is at risk of flooding if there are no gutters to divert it. This is something you want to avoid from happening. Basement flooding can create substantial damage that demands extensive and pricey repairs. If you’re looking to save money and protect your basement from flooding, it’s better to install a gutter system.

Reason #2: Yard and Landscaping Protection

A common landscaping practice is to plant shrubs and flowerbeds against the exterior walls of your home. You will need gutters to direct water away from these locations if you want them to look their best. There is a good chance that they will be over-watered even if they are not injured.

Reason #3: Erosion Prevention On Your Property

When it rains a lot, the earth around your house can get washed away. More erosion will occur the longer and more forcefully the water sits and settles down on it. In order to prevent further erosion, you should divert water away from your home.

Reason #4: Foundation Protection

If water seeps down the sides of your house, it might split and destroy the foundation. When water is slammed into even the smallest fissure, it can swiftly widen. It is critical to maintain the structural integrity of your home’s foundation in order to ensure its long-term viability.

Reason #5: Protect Exterior Paint

Staining and deterioration of the paint on the exterior of your home might occur if water is constantly flowing down the walls. For this reason, it is better to have gutters installed rather than repaint the exterior of your property, which is expensive and time-consuming.

Reason #6: Prevent Mold and Mildew Development

Mold and mildew can form in your basement, around your home’s exterior, and even under your siding if any of the above water infiltrations occur.

Reason #7: Ensure Ice and Snow Melting

Having a gutter system in place will ensure that any snow that falls from your roof is safely removed from your house. In the event of heavy snow or ice falling from your roof, your house would be unable to withstand the weight of it. People who stroll on the ground surrounding your house may also be at risk. Snow and ice can be deadly when they fall.

Understanding Gutter Sizes

Standard 5 or 6-inch gutters, as recommended by your contractor, are sufficient for the majority of homeowners. If you live in a mild climate and have standard-sized gutters, you should be fine. However, the type of roof you have, the amount of rainwater your area receives, and the slope of your roof all determine the number of gutters you may need. It’s feasible to calculate the ideal gutter size for your house and it’s definitely something we would recommend doing first. 

Two measures would suffice for a typical gable roof, which has two sides: the square footage and pitch of each side. Hip roofs with four sides, for example, require four calculations to calculate how much pressure they will place on your gutters. Gutter and downspout sizes will be determined by these calculations, together with the slope of your property and the amount of rain you forecast. The total drainage area is equal to the sum of the length and width of each side.

The Roof’s Pitch and Pitch Factor

The more rain your roof can hold, the steeper it is. You will need a tape measure and a level at least two feet long to measure your roof’s pitch factor. Set the level on the edge of the roof. Use a tape measure to measure the distance from the beginning of the roof to the midway at the 12-inch mark. The short side of the triangle has been found. As a result of your measurements, the following are the roof pitch factors:

  • 12 in 12 or higher = 1.3
  • 9 in 12 to 11 in 12 = 1.2
  • 6 in 12 to 8 in 12 = 1.1
  • 4 in 12 to 5 in 12 = 1.05
  • 0 to 3 in 12 = 1

It’s important to know these values because if your roof has a steep pitch, rainwater will flow considerably more quickly and overflow your gutters. If the slope is flat or minor, a smaller gutter may be able to manage it.

Identifying Maximum Rainfall Intensity

When it comes to determining the size of your gutters, you can use data from the United States Weather Bureau. The most rain that may fall in a 5-minute period, inches per hour, is the maximum rainfall intensity. Depending on the rainfall intensity in your area, you may require a larger gutter in order to accommodate that volume of water.

Finding The Correct Gutter Size

Knowing how much rain will fall on your roof and how much drainage space you have (calculated from the width and length of each side of your roof along with its slope) will allow you to determine what size gutters you’ll need.

In the event that you have a lower drainage area on a specific portion of your roof, always use the largest figure you’ve got.

Your adjusted drainage area can now be used to determine the optimal gutter size for your roof’s needs. Gutters come in two varieties: seamless and welded. A half-round and a K-Type. Square gutters are the K-type; half-round gutters, as the name suggests, are round. For each of these, we’ve provided sizing guidelines.


  • 2,560 square feet at 5 inches
  • 3,840 square feet at 6 inches thick Here is the suggested measurement for your shoe size.


  • A 5-inch square is approximately 5,520 square feet.
  • 6-inch 7,960-square-foot

They’re all pretty standard ideas for your house. Depending on where you reside, you may need custom-sized downspouts or additional ones if rain is a common occurrence. If the maximum rainfall intensity and your roof’s slope and square footage exceed the recommended 5 or 6 inches, you can have bespoke 7 and 8-inch gutters. Costly as they are, they will save you from the various problems that come with having too much rain around your house.

Alternative Options for Gutter Sizes

Additionally, increasing the gutter pitch, which may look a little odd but can help manage more water, is another option. Finally, if you have a large home, consider installing additional downspouts. Downspouts can be installed every 40 to 50 feet.

With gutter guards, you don’t have to get up on a ladder to clean out the clogs, making it easier to keep your gutters clear and flowing smoothly without the need to get up there.


Figuring out the right type of gutter sizes for your roof can be a tedious task. If you’re the DIY type of person this may very well be something up your alley. However, if you’re looking for a professional approach from someone who has been doing this for quite some time reach out to us. You can always text or call us at (636) 699-0449. We’re always here to help because for the best job done always choose Second To None Exteriors.

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