5-inch vs 6-inch Gutters: Make the Right Choice

Choosing between 5 and 6 inch gutters can be difficult, especially if you don’t know what you’re looking for.

For the majority of homes, 5 inch gutters are standard and you won’t need 6 inch gutters. But if your home has a roof with a steep pitch, large surface area, or heavy rainfall, 6 inch gutters may be a better option. 6 inch gutters can carry a larger amount of water before overflowing, they can carry up to 50% more water than 5 inch gutters.

But we’ll go more into detail about when to choose 5 inch gutters vs 6 inch gutters in this guide.

5-inch vs 6-inch Gutters: Key Differences

5 inch vs 6 inch gutters k-style
5-inch gutters6-inch gutters
Holds up to 1.2 gallons of water per footHolds up to 2 gallons of water per foot
Smaller roof surface (Less than 1000 sqft)Larger roof surface (More than 1000 sqft)
Lower pitchHigher pitch
Less rainfall per hourMore rainfall per hour

Making the right choice between 6-inch and 5-inch gutters can determine if you have perfectly working gutters or and overflowing disaster.

The choice will depend on three main factors: rainfall, roof pitch, and roof surface area. To figure out what gutter size you need, gutter contractors will usually use this simple formula:

Rainfall per hour x Roof pitch x Roof surface area = Total water flow

Total water flow is the most important measurement for your gutters. If you think about it, that’s what your gutters job is. Manage the water flow that comes off of your roof.

The total water flow will determine the size of gutters needed for your home. If you don’t get extreme rainfall and your roof doesn’t have a steep pitch or is unusually large, it’s safe to say that 5-inch gutters are your best bet.

Luckily, the choice can come down to common sense, but if you want to make a data-based decision, keep reading. We’ll help you figure out what you need based on a few simple measurements.

1. Amount of Rainfall in your Area

Gutter size (K-style)2 inch/hr3 inch/hr4 inch/hr5 inch/hr6 inch/hr
5 inch1250 sqft834 sqft625 sqft500 sqft416 sqft
6 inch1920 sqft1280 sqft960 sqft968 sqft640 sqft
Maximum roof size (in square feet) based on rainfall by the hour for each gutter size. Calculations taken with a roof at an incline at 1/16.

If you live an area where you get tropical storms or monsoons where the rain falls so fast you get soaked as soon as you step outside, it may be worth looking at larger gutters. If you’re in an area where the rain slowly trickles for days at a time, smaller gutters will be perfect.

If you experience heavy rainfall, you may need 6-inch gutters. However, there is a difference between a lot of rainfall and heavy rainfall. If you get a lot of rain, but it happens slowly over a long period of time, 5-inch gutters may still work.

We’re looking at the rate of rainfall, not the total amount.

That’s why it’s important to look at inches of rainfall per hour to determine if you need 6-inch gutters. A faster rate of rainfall will overwhelm smaller gutters and leading to issues like your gutter’s overflowing with water.

To figure out your rainfall per hour in your area, you can do a simple google search, such as: “your city” + rainfall per hour.

Keep in mind, global warming is contributing to more extreme rainfall year over year, so if you’re on the edge between choosing the gutter size, it could be a good idea to go a size up.

2. The Pitch of your Roof

measuring the pitch of roof with level and measuring tape

Image by BoutenkoFilms

Distance MeasuredPitch Factor
3 inches or less1
4-5 inches1.05
6-8 inches1.1
9-11 inches1.2
12 or more inches1.3
A pitch factor of over 1.1 is considered steep.

The pitch of your roof refers to the angle or steepness of your roof. If you’re roof has a steep pitch, the rain will fall down your roof faster. Remember, it’s all about the rate of the water flowing into your gutters. A steep roof will lead to faster water flow into your gutters.

There are ways to measure the pitch of your roof, but an experienced contractor can probably know just by looking if your going to need larger gutters based on the steepness of your roof.

If you want to measure it yourself, you’ll need a level and measuring tape.

Hold out a level against your roof so that it is horizontal. Then grab a measuring tape and go out 12 inches from the roof, measure downwards from that spot until it touches your roof. This downward measurement will determine the pitch factor.

Use the table above to get the pitch based on the distance you measured.

A pitch factor above 1.1 is considered steep and could be a sign that you may need 6 inch gutters. To do an even more calculated measurement, use the formula of pitch x rainfall per hour x surface area.

3. Surface Area of your Roof

pitch of roof for rainfall along with height and width. Helps choose between 5 inch and 6 inch gutters.

Do you have a big house with a large roof? Well, that can impact the size of your gutters. A bigger roof is more water that your gutters need to catch and drain away from your house.

So naturally, the surface area of your roof’s plane will also impact the size of your gutters.

A larger roof means more rainfall entering your gutters.

Your “roof’s plane” refers to the amount of roof surface area your gutters have to support.

This is a simple measurement to figure out. Take the distance from the start of your gutters to the peak of your roof. Then measure the overall distance of your gutters for that section of roof.

It will look like: roof length x gutter width = roof surface area.

This measurement will help you determine the gutter size and the number of downspouts you will eventually need.

A larger surface area = bigger gutters, smaller surface area = smaller gutters.

Note: A good rule of thumb is less than 1000 square feet can be supported by 5-inch gutters and more than 1000 square feet will need 6 inch gutters.

But there are other factors that may impact the decision between 5 and 6 inch gutters.

Other Factors that Impact Gutter Size

5 vs 6 inch gutters

Besides just water flow, there are other things that may impact gutter size.

In some scenarios, it may just be for visual appeal. We all want our homes to have nice curb appeal and gutters can play a large part in that, especially if they are painted.

Here is a breakdown of some other factors to look for:

  • Shingles Past Edge of Roof: If you’ve had your roof shingles replaced recently, they may push out too far past the gutters. This can lead to the water overshooting the gutters and falling around your home. To fix this issue, going with larger gutters, such as 6 in gutters, can work.
  • Looks More Natural: If your home has a thicker fascia (the wooden board the gutters attach to), smaller gutters can look goofy when mounted. They’ll look too small and out of place. In this case, larger gutters may be worth it to keep up the curb appeal.
  • Easier to Clean: Let’s face it. Larger gutters allow for room to scoop out leaves and gunk when cleaning time comes around. The larger gutters are also less likely to clog up.

When to Choose 5-inch Gutters

For the standard American home, 5-inch gutters will do the trick.

5-inch gutters can sustain the average amount of rainfall for the average roof. So what’s the average roof look like? The general rule of thumb is that a 5-inch gutter can sustain rainfall if the surface area of a roof’s plane is less than 1000 square feet (depending on pitch and rainfall).

A roof plane refers to the size of the section of roof that the rainfall will fall down. It’s the area of rainfall that the gutter has to catch. If you increase the area of the plane, you get more rainfall.

If you increase the pitch, or angle of the plane, the rain falls faster.

So if the the pitch is too high or there is too wide of an area, you may need to upgrade to 6-inch gutters.

The standard gutter is usually seamless, which means each section is one continuous piece. They are also in the K-style shape, which is what gives them the look that’s like crown molding, this shape allows for the most waterflow so it’s the most functional choice. For the purpose of simplicity, we are only talking about K-style gutters in this article.

When to Choose 6-inch Gutters

Six inch gutters are a great option when you need bring out the big boys. It’s for those scenarios when you are in an area with heavy rainfall and 5 inch gutters are just going to overflow.

Your roof shape can also impact the decision as well. 6-inch gutters are the go to if you have a steep roof or if you’re roof is much larger than normal. Both of these increases the amount of waterflow your gutters need to handle.

So if you home has any of these factors (or all three) go with 6-inch gutters as they’ll be a safer bet. Otherwise, 5-inch gutters will work perfectly.

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