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Rain gutters protect your home from water damage by directing runoff away from the foundation. Whether you’re considering upgrading to seamless gutters, investing in the right gutter guards, or replacing a few damaged sections, taking precise gutter measurements is imperative. Our guide explains how to safely and accurately measure your gutters, plus offers tips for choosing the right gutters for your home.
Steps to Follow
Step 1: Measure the Length of Your Gutters
Use a sturdy A-frame or straight ladder with a stabilizer attachment to reach your gutters. Carefully extend a measuring tape from one gutter end to the other. Record the measurement on paper or use your phone’s note-taking app. If your tape measure cannot span the entire length, use a piece of chalk to mark your place to demarcate the first measurement before moving on to the next section.
Repeat this process until you’ve measured your entire gutter system, or the portion relevant to your project. Add all your gutter measurements together to determine how many linear feet you need.
Step 2: Measure the Width of Your Gutters
Measure your gutters’ width at three points: both ends and the midpoint. Add these numbers together, and divide the total by three to get an average width. Because slight variations are possible, taking an average of these three measurements will provide the most accurate number.
Step 3: Measure the Depth of Your Gutters
Starting from the top, measure down to the gutter’s bottom edge to determine depth. As in the previous step, measure the depth at both ends and the middle and use the average.
Wider gutters are generally deeper, as depth typically increases with width. Depth also varies by style. For instance, K-style gutters are deeper than half-round gutters. As a result, 5-inch K-style gutters can hold a greater volume of water than 5-inch half-round gutters.
Step 4: Measure the Slope of Your Gutters
Gutters need to slope at least 1/4 inch for every 10 feet of length to drain well. However, a more common slope is 1/2 inch per 10 feet. That means if your gutters are 30 feet long, the side with the downspout should be 3/4 to 1 1/2 inches lower than the other end. The tilt will ensure that water flows seamlessly toward the downspout.
Make sure your gutters are properly sloped. If you have a gutter run with a downspout at both ends, the gutter’s highest point should be in the middle, with a gentle slope on either side.
Step 5: Measure the Shape of Your Gutters
Use a pencil and paper to sketch a detailed outline of your gutter’s cross-section. Label your sketch with the gutter’s dimensions. If you’re not confident in your ability to accurately sketch the profile, consider tracing it.
K-style and half-round gutters are the two most common shapes. K-style gutters have a shape that resembles crown molding, while half-round gutters are semi-circular.
Safety Tips for Measuring Gutters
Measuring gutters is a straightforward do-it-yourself (DIY) job, but it does demand attention to detail and safety. Follow these tips to avoid accidents.
- Invest in a sturdy ladder. A wobbly ladder can lead to tragic mishaps, so make sure yours is in good condition.
- Avoid windy or rainy days. Wait for a calm, sunny day. Rain will make your ladder and roof slippery, and wind will make you and your ladder less stable.
- Wear protective gear. Wear shoes with a nonslip sole. Consider wearing work gloves to protect your hands from sharp edges and debris, especially if you plan to clean or repair your gutters.
- Use a stabilizer attachment. Resting a straight ladder against your gutters can damage them. Use a stabilizer or standoff attachment that allows the ladder to rest against the roof.
- Find level ground. Place your ladder on flat, firm ground or use ladder levelers to compensate.
- Recruit help. Ask a friend or family member to help steady the ladder, write down gutter measurements, and pass you tools to minimize trips up and down the ladder. Having a partner also helps in case of an emergency.
- Keep your hands free. Use a tool belt, pouch, or bucket attached to your ladder to hold tools and keep both hands free.
- Stay aware of your surroundings. Be cautious of power lines and other obstacles.
- Avoid stretching. If you can’t easily reach an area, return to the ground and reposition the ladder. Overreaching can cause you to lose your balance.
- Follow the 4-to-1 rule when positioning the ladder. To make sure you stay on a ladder positioned against a straight angle, you must angle the ladder. Divide the surface’s height you’re setting the ladder against by four. Then position the ladder’s base that many feet from the building’s side—1 foot away for every 4 feet of height.
How to Choose the Right Size and Type of Gutters
If you’re installing new gutters, consider upgrading to a larger size or higher-quality material. To determine the right size of a gutter, calculate the roof’s adjusted square footage. Here’s how:
- Determine the roof’s drainage area. Measure the length and width of each roof section. Multiply each set of numbers together to find the area, then add the products to find the roof’s total square footage.
- Determine the roof pitch and multiplier. Use a tape measure and a 12-inch level to measure the roof’s pitch, or how many inches it rises across a 12-inch run. Once you know the pitch, use the chart below to find the corresponding roof-pitch factor:
- 3 inches or less = 1
- 4 to 5 inches = 1.05
- 6 to 8 inches = 1.1
- 9 to 12 inches = 1.2
- 12 inches or higher = 1.3
- Determine the maximum rainfall intensity. Look up the amount of rainfall for your location using the National Oceanic and Atmospheric Administration’s Precipitation Frequency Data Server (PFDS). For data type, select “precipitation intensity.” The bolded number in the fourth column of the first row (5-minute duration, 10-year recurrence interval) is the number you need.
- Calculate the adjusted square footage. Multiply the roof square footage by the roof pitch multiplier by the maximum rainfall intensity. Use the result to determine whether you need a larger gutter size. Here’s a quick guide:
- 5-inch half-round: Up to 2,500 square feet
- 6-inch half-round: For up to 3,840 square feet
- 5-inch K-style: For up to 5,520 square feet
- 6-inch K-style: For up to 7,960 square feet
When choosing the right gutter size, compare different styles and materials. K-style gutters can handle more water than half-round gutters, but half-round gutters look better on historic homes. Aluminum and vinyl gutters are cost-effective and come in a variety of colors, but they aren’t as durable as stainless steel, copper, or zinc.
Weigh the cost of certain upgrades, such as gutter guards and seamless gutters, against the improved performance and longevity they promise.
Gutters need to be properly sized and installed to perform well. Follow the steps in our guide to get the measurements you need before repairing or replacing your gutters. Accurate gutter measurements will help you choose the right size and type for your home.
How We Chose the Top Gutter Guard Providers
We researched and analyzed dozens of gutter guards and gutter guard companies to create an in-depth review methodology. We formulated a rating system based on the factors homeowners find most important. We evaluated each provider’s gutter guard design and aesthetics, service offerings, customer service and communication, quote process, warranties, and financing options.
We created a separate rating system for DIY-installed gutter guards sold on retailer sites. We evaluated these guards based on their quality of materials, aesthetics, communication, warranty, customer reviews, and cost.
We evaluated each provider’s reputation using independent, third-party sites such as the Better Business Bureau (BBB) and Google My Business pages. For products, we analyzed the customer reviews on whichever online retailer primarily hosts the product.
How To Measure Gutters FAQ
How do I know what size my gutters are?
To determine your gutter’s size, measure the width at each end and the midpoint. Then average these numbers to get the most accurate measurement.
What is the most common gutter size?
5-inch and 6-inch gutters are the most common sizes for residential gutters.
How much do new gutters cost?
The cost of new gutters varies depending on the style, size, and material. The average cost of gutters for a single-story home is $1,200. Low-end options, such as vinyl, cost around $3 to $6 per linear foot, while high-quality options, such as copper, may cost from $25 to $40 or more per linear foot.