How do you calculate linear feet of gutters?

Calculating the linear feet of gutters needed for a home is an important part of properly installing a gutter system. The linear feet measurement allows you to determine how much gutter material to purchase and accurately price out the job. In this article, we’ll walk through the basics of measuring linear feet for gutters and provide step-by-step instructions for calculating your needs. We’ll also cover some key factors that can impact your gutter footage like downspouts, corners, and drainage requirements.

What is linear feet?

Linear feet simply refers to the measurement of length in a straight line. When talking about gutters, it’s measuring the total length of the gutter system following its path around the roofline. This accounts for all the straight sections, corners, turns, and angles of the gutters. It’s sometimes estimated by measuring just the perimeter of the roof, but accurately calculating linear feet takes into account all the nuances of the specific gutter system.

Why is linear feet important?

Knowing the linear feet for your gutter project is crucial for:

  • Ordering the correct amount of gutter material – Whether you choose seamless aluminum, vinyl, copper, or steel gutters, you need to know the linear footage to buy enough of the right gutters for the job.
  • Pricing materials and labor – Contractors base their project estimates on the linear feet to cover material and installation costs accurately.
  • Comparing gutter system options – Alternative gutter styles and sizes will impact the required linear footage.
  • Determining the numbers and placement of downspouts – Downspouts need to be spaced according to the gutter linear feet to effectively drain rainfall.

Getting an accurate linear feet measurement is an essential part of gutter system planning and installation. Now let’s look at how it’s calculated.

How to Calculate Gutter Linear Feet

Figuring out your gutter linear feet involves breaking down the roof into segments and adding up the measurements. Here are the key steps:

1. Break the roof into sections

Look at the roof and divide it into straight-line sections based on the roof edges and angles. For simple roof shapes like squares or rectangles, you may only have two sections. For more complex roofs, you’ll likely have four or more sections.

2. Measure each roof section

Use a measuring tape to measure each section of roofline from one end to the other. For second story roofs, you may need a longer tape measure or ladder to safely reach up and get accurate measurements. Record each measurement.

3. Add up all the section measurements

Once you have the length of every roof section measured, add all the section measurements together to get your total linear feet needed.

4. Account for corners and ends

Add additional linear feet to account for the corner pieces and end caps that transition between straight gutter sections. A good rule of thumb is to add 5 linear feet for every corner and 2 linear feet for every end.

5. Factor in drainage requirements

The number and placement of downspouts you need for adequate drainage will depend on your total gutter linear footage. Generally, gutters should slope 1 inch for every 20 feet of length, with downspouts every 40 feet. Adjust your linear footage as needed to meet drainage requirements.

Once these steps are completed, you have your total linear feet calculated! Now let’s go through some examples.

Gutter Linear Feet Examples and Calculations

To better understand how linear feet is calculated for gutters, let’s look at some examples for different roof types and drainage needs:

Simple Ranch House Roof

For a one-story ranch style house with a simple rectangular roof:

  • Roof Section 1 = 50 feet
  • Roof Section 2 = 75 feet
  • 2 corners x 5 feet each = 10 feet
  • 2 end caps x 2 feet each = 4 feet

Total linear feet = Section 1 + Section 2 + Corners + End Caps
= 50 ft + 75 ft + 10 ft + 4 ft

= 139 ft

Two-Story House with Extension

For a two-story house with an L-shaped roofline:

  • Roof Section 1 = 60 feet
  • Roof Section 2 = 75 feet
  • Roof Section 3 = 40 feet
  • Roof Section 4 = 25 feet
  • 6 corners x 5 feet each = 30 feet
  • 4 end caps x 2 feet each = 8 feet

Total linear feet = Section 1 + Section 2 + Section 3 + Section 4 + Corners + End caps
= 60 ft + 75 ft + 40 ft + 25 ft + 30 ft + 8 ft
= 238 ft

Drainage Adjustments

For a 40 foot roof section with a downspout needed every 40 feet:

  • Roof Section = 40 feet
  • Add 1 downspout = 5 extra feet

Total linear feet = Section length + Downspout adjustments
= 40 ft + 5 ft
= 45 ft

These examples illustrate how the linear feet formula can be adapted to fit any roof shape or drainage requirements. The key is taking accurate measurements and factoring in all angles, transitions, and downspouts.

Tips for Measuring Linear Feet

To ensure you get an accurate linear footage calculation, keep these tips in mind:

  • Use a steel measuring tape for best results. Cloth tape measures can stretch over time.
  • For high roofs, use a tall ladder or telescoping pole to reach the edge safely.
  • Have an assistant help record measurements from the ground for convenience and safety.
  • Take measurements from the roof edge, not just the house edge which may differ.
  • Round measurements up to the nearest half or full foot.
  • Double check your math when totaling up sections and additions.
  • Account forceiling height if measuring from ladders for second story roofs.
  • Remember that gutters need a slope of 1 inch drop for every 20 feet.

With some careful measuring and number crunching, determining accurate linear feet is straightforward. Having the right gutter length calculated makes ordering materials and installing new gutters much simpler.

Gutter Size and Style Impact

The gutter system you choose can have an impact on the linear feet required:

Larger Gutters

If wider 6-inch gutters are used instead of 5-inch, the linear footage may reduce slightly since wider gutters have greater capacity.

Different Styles

The profile of the gutter impacts connections. Rounded K-style gutters require less corner pieces than boxier half-round gutters.

Seamless vs. Sectional

Seamless steel or copper gutters won’t need connectors between sections. Sectional vinyl gutters require joining pieces to connect 10 foot sections.

More Downspouts

Adding more downspouts than required can increase the linear length slightly.

Consider the style and size of your new gutter system when estimating linear feet. Their unique factors can result in footage differences.

Advanced Techniques for Measuring

For irregularly shaped roofs or multi-level homes, additional techniques can help capture accurate measurements:

Laser Measuring Tools

Laser distance measurers use sensors and laser light to measure roof lengths with high precision. Useful for angled or high roofs.

Aerial Measurement

Using aerial images from satellite or drone photography allows for measuring roof dimensions remotely. Helpful for homes with many roof levels.

3D Modeling

Creating a 3D model of the home virtually can provide detailed measurements for complex designs like dormers, turrets, or curved walls.

Measuring Software

Specialized mobile apps use images and AI to measure roof lengths down to the inch quickly. Convenient for odd-shaped roofs.

For challenging measurement scenarios, these high-tech options can provide easier and more precise linear footage numbers.

Cost Factors per Linear Foot

Linear feet impacts the installed cost for gutters in a few important ways:

  • Material Cost – More linear feet uses more material, directly increasing material costs.
  • Labor Time – Longer gutter lengths take more time to install, increasing labor hours/costs.
  • Corners/Outlets – More corners or downspouts add to costs per linear foot.
  • Accessibility – Roofs that are higher or harder to access drive up per foot costs.

When calculating your total project cost, account for these key factors multiplied by your linear footage. This provides the most accurate estimate of your gutter installation investment.

Measuring Do’s and Don’ts

To wrap up, here are some key dos and don’ts for measuring linear feet correctly:


  • Take measurements from the actual roof edges
  • Account for all sections, corners, ends, and downspouts
  • Use a steel measuring tape
  • Have someone assist with recording numbers
  • Round up to the nearest foot
  • Double check measurements


  • Rely on the building footprint alone
  • Use cloth tape measures that can stretch
  • Take shortcuts that underestimate length
  • Forget slope requirements every 20 feet
  • Assume roof edges match house edges

Following these do’s and don’ts will help ensure your gutter project starts out on the right foot with an accurate linear footage calculation.


Determining your gutter system’s linear feet is an important first step in any gutter installation or replacement project. By breaking the roof into sections, taking careful measurements, and calculating additional parts like corners and downspouts, you can accurately measure the total linear footage required. Factoring in the style and size of gutters along with difficult access or complex roof shapes allows for a true total footage calculation.

With the right techniques and diligent measuring, calculating linear feet for gutters is a manageable process. The precision of your measurements also gives you a reliable basis for comparing gutter material options, estimating project costs, and ordering the correct amounts of gutters the first time. Taking time to accurately determine your linear feet ultimately saves time, money, and headaches down the road.

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