What is the Standard Gutter Size?

What is the Standard Gutter Size?

You probably don’t think about your gutters often. That’s especially true if they’re designed right and doing a proper job of taking water from your roof to the ground. But if you need to replace your gutters, it helps to understand standard gutter size. Find out more about gutter dimensions below so you can make an educated choice.

If there’s a standard gutter size, it would be 5 inches for seamless gutters. That’s what many residential homes have, though you can also opt for other common choices. Those can include 4-inch or 6-inch gutters or, in special cases, 7-inch gutters.

How to Determine Gutter Dimensions for Your Home

If you already have gutters installed and need to replace all or part of the system, you can measure the existing gutters to determine how wide they are. You’ll also want to ensure you’re matching the shape and material of your existing gutters.

However, if you want to have a whole new gutter system installed, you’ll need to take some roof measurements to understand what size gutter is best. Typically, the larger your roof surface — and the more it slopes — the bigger the gutter size required. That’s because more water will run off faster.

Here’s a step-by-step guide to figuring out proper gutter dimensions for your home.

  • Calculate square footage of the roof surface.
    • Measure the lengths and widths of each area of your roof.
    • Multiply each length and width to get the square footage of that area.
    • Add those numbers to get the total square footage.
  • Get the pitch of your roof. 
    • Hold a level horizontal with one end touching the roof surface.
    • Measure 12 inches along the level from the end that’s touching the roof.
    • At that point, measure the space from the roof to the bottom of the level — that’s the pitch.
  • Multiply the roof square footage by a number determined by the roof pitch.
    • 0 – 3 inches, no multiplier
    • 4 – 5 inches, multiply by 1.05
    • 6 – 8 inches, multiply by 1.1
    • 9 – 11 inches, multiply by 1.2
    • 12+ inches, multiply by 1.3
  • Use the resulting number to choose gutter measurements.
    • For K-style gutters, 5-inch gutter dimensions should work if the total number is 5,520 to 7,500.
    • You might need larger gutters if the number is higher.

What Size Downspout Will You Need?

Gutter size isn’t the only consideration when you’re repairing an existing roof drainage system or installing a new one. You’ll also need the right downspout size. Downspouts are the pipes that run down the side of and away from the home. They channel water from the roof away from the house.

Usually, if you have a 5-inch K-style gutter, 2×3-inch or 3×4-inch downspouts are good options. Some options might require retrofitting by trimming parts to ensure an appropriate connection.

Professional Help With Gutters

As you can see above, installing gutters can be complex. Ensuring that you get the gutter dimensions right is only the first step in the process.

Whether a standard gutter size is right for your home or you have specialty needs that require customization, Thompson Creek may be able to help. The Thompson Creek replacement gutter system even reduces the need for regular maintenance because it includes gutter hoods that filter out a lot of common debris.

Contact Thompson Creek today to find out how we can help with replacement gutters — whether you already know what size you need or not.