Master the compass and you may never get lost again. (Photo: Klaus Vedfelt/Getty Images)

Learn How to Use a Compass and Never Get Lost Again

GPS units sometimes fail—you owe it to yourself to know how to use a trusty compass

Leah Qiu

from Backpacker

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Master the art of navigation and you’ll never lose your way again. In our seven-part Backcountry Navigation course on Outside Learn, you’ll get versed in everything you need to navigate on- and off-trail, from using GPS and digital maps to old-school wayfinding with a paper map and compass. Join the class now and learn at your own pace. 

Sure, not all who wander are lost. But when you’ve been walking in circles for hours and your day hike is stretching into an overnight, that saying is a cruel joke. The solution? Don’t get lost in the first place. Learning how to use a map and compass is something all hikers and backpackers need to do.

Even experienced backpackers sometimes neglect their navigation skills, but when the trail peters out or is covered by snow, knowing how to blaze your own path is absolutely essential. And even in the age of GPS and smartphones, the most dependable way to make sure you stay on track is to carry a map and compass and know how to use them. Below, we’ll cover both the basics and some finer points of compass navigation.

More: Get unlost with our Backcountry Navigation course on Outside Learn.

Why Should I Learn to Use a Compass?

With the advent of GPS, navigating by compass has become something of a lost art. It’s easy to see why: under clear skies, modern GPS receivers can determine a user’s location accurately and quickly with little to no user skill necessary.

But here’s the thing: GPS units are electronic, and electronics fail at the most inopportune times. Sometimes they run out of battery; sometimes, after years of use, they fail. Furthermore, they can usually tell which way you’re facing only once you’re on the move.

Compasses, on the other hand, are nigh indestructible. They don’t take batteries, don’t have screens to break, and don’t need software updates. And when protected with either waterproof coatings or careful storage, maps rarely fail. Keeping these two simple items in your pack—and knowing how to use them—is a small step that could save you a lot of trouble.

Tip: Once you’ve got the hang of navigating the old-school way, you can use apps like Gaia GPS to check your work or get more specialized data like slope angle.

Magnetic compasses use the earth’s magnetic field. (Photo: Massimo Colombo/Getty Images)

Get to Know Your Compass

A compass is the most reliable navigation method—but it’s no good unless you know your way around it. Different kinds of compasses have different parts, but here are some common components.

Baseplate: A clear back that lets you see the map underneath. The ruled edge helps with triangulation and taking your bearings.

Direction-of-travel arrow: This shows you where to point your compass when taking a bearing.

Index line: An extension of the direction-of-travel arrow that indicates where to read bearings.

Rotating bezel: A circular area marked with numbered degrees (clockwise) from 0 to 360.

Magnetized needle: Located inside the bezel, it always points to magnetic north, not true north. (They’re hundreds of miles apart.)

Orienting arrow: It helps line the bezel up with the directions on the map.

Declination scale: Hash marks on the inside of the bezel designed to help adjust declination. (Don’t know how to do that? Read on.)

Correcting for Declination

One of the tricky parts of navigating with a compass is that magnetic north isn’t the same as true north. The angle between the two—known as the declination—varies with your location. It also gradually changes over time as the earth’s tectonic plates shift. If you don’t adjust your compass to compensate, you’ll find yourself headed in the wrong direction.

The easiest way to find the angle of declination is to check your map: most have declination diagrams, along with the date it was last revised. Because declination changes over time, newer maps will have more accurate figures. There should be an angle and a direction—for example, 8 degrees east.

Working from an older map? Check online. There are several different services that can use the location you’ll be hiking in to calculate your declination.

Once you have your declination, subtract it from your compass bearing for west and add it for east. If you have trouble remembering that rule, try this mnemonic: Maps Tell Almost Everything (Magnetic to True: Add East).

Fun fact: compasses first appeared in China around 200 B.C. and were likely used for fortune-telling. Declination wasn’t discovered until roughly A.D. 720.

lensatic compass
Lensatic compasses are precise but have a learning curve. (Photo: Adamantios)

What Are the Different Types of Compasses?

While there are many different kinds of compasses on the market, the most common for backpackers is the baseplate compass, which consists of a liquid-filled compass face attached to a flat, clear piece of plastic. Besides being cheap and simple, a baseplate compass, with its see-through design, is easy to use with a map.

Also popular are lensatic compasses, which flip open like a locket and use a sighting wire in the cover and a rear lens to take highly accurate bearings. While they have the advantage of being precise and durable, lensatic compasses have a slightly steeper learning curve.

Because baseplate compasses are the most widely used, our instructions here will focus on them. If you have a lensatic compass, your steps may vary slightly. Metal interferes with compasses’ magnetic needles, so avoid spreading your map out on a car hood.

Want to triangulate your location? Start by identifying a few landmarks. (Photo: Ken Conger/NPS)

How to Find Your Location with a Compass

Figuring out your location with a map and compass is easy if you know how. First, you’ll need to be able to find at least two known landmarks. (Mountains and lakes are both good choices.) If you can find a third, even better. As always, remember to adjust for declination.

1. Using your compass, orient your map so that north is pointing to true north. (Pro tip: make sure the fixed grid lines on your compass line up with the north-south grid lines on your map.)

2. Take a bearing on your first landmark: Line up your direction-of-travel arrow with your landmark, then rotate the bezel until the needle lines up with the marking for north. (The number next to the index line is your bearing—more on that to come.)

3. On the map, place one corner of your compass’s straightedge on the landmark, then rotate the entire compass until the needle lines up with north on the bezel. Using a pencil, draw a line aclong the edge.

4. Repeat steps 2 and 3 for your other landmarks. The point where all the lines intersect is your approximate location.

How to Find Your Bearings with a Compass

If you already know your location, you can use your compass to figure out how to get to any point on your map. After adjusting your compass for declination, start by orienting your map to true north, as in the instructions above.

1. Place the corner of your compass’s baseplate on your location, then rotate your entire compass until the straightedge forms a line between your location and your destination.

2. Rotate the bezel until the grid lines on the baseplate match the grid lines on the map.

3. Read the number next to the index line—this is your bearing.

4. Holding the compass level in front of you, turn your body until the north arrow on the bezel matches up with the compass’s needle. Your direction-of-travel arrow should now be pointing toward your destination.

Using Your Smartphone as a Compass

Your smartphone can do everything else, so it shouldn’t come as a surprise that it has a compass built into it. With the right app (try Digital Field Compass for Android, or for a more full-featured experience, Gaia GPS for iPhone and Android), you can use your phone as a navigation device, no GPS required.

The apps use your phone’s magnetometer. After a simple calibration process, it can not only do whatever a compass can do, but can even lock onto a bearing well enough to tell you when you’ve gone astray.

Of course, phone-based compasses come with a few big caveats. The biggest: just like the GPS on your phone, all of these apps require a charged battery to work. That’s why we recommend that everyone learn how to use a normal, analog compass. You can count on it to continue working no matter what you put it through. Once you’ve fully developed those skills, you can use your phone’s GPS without fear of running out of juice.

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Lead Photo: Klaus Vedfelt/Getty Images