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How to Set Declination on a Compass

how to set declination on a compass

A compass is an essential tool when doing any outdoor activity. Its ability to identify land features, orient the map, or even locate your positions are great features that can help make hikers’ lives a lot easier. Unfortunately, not everyone knows how to use a compass, especially in setting its declination.

But how to set declination on a compass? Setting the declination of a compass is an important skill to let you navigate an area easily during the hike. Setting the declination will compensate for the angle between the true north and the magnetic north. For more information, read this article and learn the process of declination on a compass.

Setting Declination on a Compass

If you want to know how to set the compass’s declination, you must first be familiar with the difference between magnetic north and true north. If you own a globe, it is very easy to say that the true north is on the top of that globe.

In addition, if you find yourself holding a true map, you will notice the complicated set of arrows pointing to the north. You will also notice vertical and horizontal lines on the map, which is very important during your compass navigation.

On the other hand, the magnetic north is the direction where the compass’s needle points to a particular direction. The movement of the compass’s needle is influenced by the magnetic fields of the earth and all other core elements.

This situation makes the magnetic north reading fluctuate depending on your current location on the globe. The angle formed in the disparity of the true north and magnetic north is what you called declination.

It is important for you to calibrate the compass for it to make up the declination angle. Doing this action will allow you to use the compass’s needle in navigating your preferred direction in reference to the true north.

Step-By-Step Guide

setting declination in a compass

Please find below the step-by-step guide in setting the declination angle of the compass.

1. Finding the Declination

The initial step is to look for the declination value of the place you are currently located. As I have mentioned earlier, the declination value varies depending on your current location on the globe.
Once you plan to hike in a particular area, you need to check first on the declination value before using the compass. If you have an actual topographic map, you will likely find the declination value list in the legend section, but these values are also not reliable.

The reason for this issue is that the declination changes slowly over time. For a more accurate declination value, you may check the National Oceanic and Atmospheric Administration (NOAA) website because they have the latest declination data.

2. Setting the Declination of a Non-Adjustable Compass

If you are new to hiking or any other outdoor activity, there is a chance that you still are not equipped with advanced tools and equipment, including an adjustable compass. If you own a non-adjustable compass, please remember our guide below:

After finding the declination value of your current location, always remember that any reading will be off in relation to the declination value of your current location every time you use the compass.

Meaning, every bearing you work with, you will need to make the declination adjustments based on the declination value in your current location.

Remember that any positive number is an east declination while a negative number is a west declination.

Transferring a magnetic bearing from the field to your map, all you have to do is add the declination value for you to get the real bearing. On the other hand, the west declination will be deducted since you are dealing with a negative number.

When doing the other way around when transferring a bearing from a map to the field, just subtract the declination value for you to have the magnetic bearing to follow. Likewise, for any west declination, it will be added because you are subtracting a negative number.

3. Setting the Declination of an Adjustable Compass

If you are dead serious in your hiking activity, there is a great chance that you already have an adjustable compass with you. This advanced compass will let you set the declination easily.

Most of the top brands differ in the way they set the declination value of the compass. All you have to do is follow the instruction, which is very easy, and you are good to go. Most of these top brands usually come with an adjustment key to change the indicator to the required reading.


If you plan to take hiking seriously, learning how to set declination on a compass is extremely important. It is essential knowledge that will help you when navigating in an unfamiliar location. Setting the declination is also one requirement in using the compass correctly.

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