When I started working in the fence supply business fifteen years ago, I quickly learned that the most common mistake homeowners make when ordering a fence isn’t picking the wrong style or color—it’s getting the measurements wrong. I’ve had customers show up at our warehouse with a tape measure that’s stretched out, a notebook full of scribbled numbers that don’t add up, and a story about how they “just guesstimated” because the neighbor’s fence looked about the same size. Nine times out of ten, that leads to ordering too little or too much material, missing a critical corner, or running into an underground utility line that ruins the whole day. Measuring for a fence isn’t just about numbers—it’s about doing it right the first time, saving you time and money, and making sure your fence actually fits the space it’s supposed to protect. Today, I’m walking you through every step I teach our team to walk customers through when they order a fence from us. Fence
First, let’s talk about the basics: safety before measurement. I can’t stress this enough. Before you even pick up a tape measure, you need to call your local utility marking service. Every area has one—usually a free service that will send someone out within a few days to mark where gas, electric, water, and sewer lines are buried in your yard. I’ve had customers start digging post holes only to hit a water line 18 inches deep, and that’s a nightmare you don’t want to deal with. Not only is it a hassle to fix, it can cost hundreds of dollars in repairs, plus you might have to wait for the utility company to come out and make the line safe. It only takes a five-minute phone call to set this up, and it’s non-negotiable. Mark those lines with bright paint or small flags, and don’t put a post hole within two feet of any marked line. That’s step one, no exceptions.
Next, map out your property lines. This is another thing many people skip, and it comes back to haunt them. A fence that’s built three inches over a neighbor’s line is a dispute waiting to happen, trust me. Your property lines are on your deed, usually in a document called a plat map that your county assessor’s office has online. If you can’t find it online, stop by the office in person—they’ll print you a copy for a few dollars. Take that plat map, and walk your property with a metal detector or a string to find the actual corner markers. Sometimes the wooden stakes or metal pins are still there; sometimes they’re under years of grass or dirt. Once you find them, mark each corner with a small flag or a can of spray paint. This is critical because your fence should sit entirely on your property, not overlapping with your neighbor’s. If you have any questions about where the line is, call the neighbor and ask—most people are reasonable, and it’s way better to talk this out before you start building than after your fence is up and someone is upset.
Now, let’s get to the actual measuring. Let’s start with straight, simple sections first, like backyard fences that run along a single side of the property. Take your tape measure and start at one corner marker. Pull it straight along the property line to the next corner, and write that number down. Repeat for every straight segment of your fence. But here’s a pro tip: don’t just measure once. Measure each segment two or three times. I’ve had customers call us saying they ordered 100 feet of fencing and it’s only 95 feet—turns out they stretched the tape measure too tight the first time, or didn’t hold it straight against the ground. For longer segments, get a friend to help you: one person holds the end at the first marker, the other walks ahead with the tape, keeping it level (not sagging in the middle) and straight. Sagging tape adds a foot or more to your measurement, which means you’ll end up with gaps when you install the fence. For segments that have obstacles—like trees, flower beds, or garden sheds—measure around them. Mark where the obstacle starts and ends, then add those two lengths to the lengths on either side. For example, if a tree is two feet wide between two points, add that two feet to the total for that section.
Now, corners. This is where many people mess up, especially if it’s a 90-degree corner (the most common kind, where two sides of your property meet at a right angle). To make sure your fence is square at the corner, you can use the 3-4-5 method. Here’s how it works: at your first corner, measure 3 feet along the direction of one side, mark that point. Then, from the same corner, measure 4 feet along the direction of the other side, mark that point. Now, measure between those two marks. If the distance is 5 feet, the corner is perfectly square. If it’s less than 5 feet, the corner is too sharp; if it’s more than 5 feet, the corner is open. Adjust until it’s exactly 5 feet apart. That method has been used for centuries to make sure fences and buildings are straight, and it works every time. For corners that aren’t 90 degrees—like a sloped lot or a property with an odd angle—you can either use a laser level (if you have one) to find the angle, or take two measurements from the corner to the next two points, then use basic geometry to figure out the length. If you’re not good with math, just take two measurements along each side of the angle and add a little extra material—better to have a foot or two extra than to be short.
Sloped yards are another big one, and this trips up so many people. If your fence runs along a hill that slopes up or down, you can’t just measure the straight horizontal distance. If you do, your fence will look wavy and uneven when it’s installed. For sloped sections, you have two options: follow the “step” method (also called racking) for your fence panels, or measure along the slope if you want a flat top. Wait, let’s explain that clearly. If you want a fence that looks level along the top (most people do), you need to measure the vertical change in the slope. For example, if the slope drops 2 feet over a 20-foot horizontal length, you’ll adjust each post height to follow that drop, so the top of the fence is even. To measure this, start at the top of the slope, hold your tape measure level, and measure the horizontal distance to the point where the next post will go. Mark that point, then measure how much the ground has changed (up or down) from your first post. Write that number down for each post. If you use pre-assembled fence panels (which most of our customers do, because they’re easier to install), you can buy “racking” panels that adjust to small slopes without cutting, or you can cut each panel to fit the slope. If the slope is very steep, it’s often better to use individual pickets and rails, or to adjust post heights to follow the grade. The worst thing you can do here is stretch your tape along the sloped ground and call that the length—you’ll end up with a fence that’s too long when you try to level the top, and you’ll have to trim or order more material.
Gates are another part that’s easy to mess up. First, decide how many gates you need. Most people want one gate for the backyard, and maybe one for a side yard or driveway. The size of the gate depends on what you’re going through. If it’s a pedestrian gate (for people to walk through), a 3-foot or 4-foot wide gate is standard. If you drive a lawnmower, ATV, or car through, you’ll need a 10-foot or 12-foot wide gate. To measure for a gate, measure the clear opening you have between two posts. Don’t just measure the space between the posts—leave an extra inch on each side for the gate hinges and latch. For example, if your posts are 38 inches apart, a 36-inch gate will fit perfectly (38 minus 1 inch on each side equals 36). If you don’t leave that extra space, the gate will rub against the posts or not close all the way. Also, make sure you measure the height of the gate to match the height of your fence—no one wants a gate that’s shorter than their fence, it looks silly and defeats the purpose of security or privacy.
Wait, what about obstacles like trees, utility boxes, or mailbox posts? This is part of measuring too. If you have a tree trunk that’s in the path of your fence, mark where it starts and ends, and adjust your post layout to go around it. Most fence posts are spaced 6 or 8 feet apart, so you can shift a post to avoid the tree trunk without throwing off the whole line. For utility boxes, check with your local company to make sure you can build around them, and leave at least a foot of space on each side so you can access the box if you need to. The same goes for mailbox posts—your fence shouldn’t block the mailbox, and most areas have laws about how close a fence can be to a driveway or road, so double-check your local zoning rules before you finalize anything. A lot of people forget zoning, and end up having to take down part of their fence because it’s too close to the street. That’s a big waste of time and money, so do a quick check online or call the zoning department before you buy materials.
Now, let’s talk about common mistakes I see every day. First, not measuring twice. I can’t tell you how many times a customer has told me they measured once, ordered, and realized they were 10 feet short. Measuring twice takes five extra minutes and saves you hundreds of dollars in extra material. Second, not accounting for post holes. Wait, when you order fence panels, the total linear feet of panels is the length you need for the fencing part. But the posts are separate. Most fence posts are spaced 8 feet apart, so for every 8 feet of fencing, you need one post, plus the two end posts. For example, if you have 100 feet of fencing, that’s about 12 posts (100 divided by 8 is 12.5, so round up to 13 total posts, including two ends). If you forget to order extra posts, you’ll be stuck driving to the store mid-install, which is annoying. Third, ignoring sag in long tape measures. Over time, cheap tape measures stretch, so if you have an old one, borrow a new one or use a laser measure if you have access to one. Laser measures are great for long, straight segments—just make sure there’s nothing blocking the laser line, like a tree or a shed. Fourth, not checking the grade. As I said earlier, sloped yards trip everyone up. Take the extra time to measure the vertical change, and don’t just go by the horizontal distance.
Once you have all your numbers written down, here’s a quick way to double-check. Add up all the straight segments, add the extra length for gates, add a 5-10% buffer for mistakes, cutting, or adjustments. That buffer is key. Even if you measured perfectly, you might cut a rail wrong, or need a little extra length at a corner, so having a small amount of extra material is way better than being short. For example, if your total linear feet of fencing is 150 feet, order 157 or 165 feet to be safe. For posts, order two extra posts—way easier to have a left over than to run out.
At our company, we have a team that helps customers walk through all these steps, even if you’re not sure. We get it—measuring for a fence can be overwhelming, especially if you’ve never done it before. That’s why we’re here: to make sure you get the measurements right the first time, so your fence installation goes smoothly. Whether you need help marking your property lines, calculating how many posts and panels you need, or figuring out how to measure a sloped yard, we can guide you every step of the way.
If you’re ready to order your fence, or if you have questions about measuring, don’t hesitate to reach out to our team for a consultation. We work with homeowners, contractors, and anyone who needs a quality fence at a fair price, and we’ll make sure you have all the information you need to get your project done right.
Interior Material References:
- American Fence Association. Fence Installation Best Practices Guide. 2022.
- International Code Council. Residential Fence and Barrier Code Requirements. 2021.
- National Utility Locating Contractors Association. Safe Digging Guidelines. 2020.
Linyi Xingang International Trade Co., Ltd.
We are one of the most professional fence manufacturers and suppliers in China. With abundant experience, we warmly welcome you to buy high quality fence made in China here from our factory. If you have any enquiry about quotation, please feel free to email us.
Address: 13th Floor, Building B, Central Times Square, Beicheng New District, Lanshan District, Linyi City, Shandong Province
E-mail: vincent@cnxingang.cn
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