We are independent & ad-supported. We may earn a commission for purchases made through our links.

Advertiser Disclosure

Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.

How We Make Money

We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently from our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What Is Declination?

Mary McMahon
Updated May 17, 2024
Our promise to you
WiseGeek is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At WiseGeek, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

In the study of geomagnetism, declination is the angle between true and magnetic north, while astronomers employ this term in the coordinate system they use to describe fixed positions of stars in the celestial sphere. The intended meaning is usually clear from the context where the term is used. In both cases, it allows for very precise location measurements, a critical necessity when a small error can translate into a significant distance on land or in space.

The Earth's magnetic field is complex. It can vary from point to point, and over time, magnetic north and south tend to wobble around the true north and south poles. Depending on where and when someone takes a compass bearing, the accuracy of the compass in terms of locating true north can be quite variable. In some parts of the world, for example, the declination may be as much as 30 degrees. This means that when the compass points north, true north is actually 30 degrees away.

Declination charts for the surface of the Earth are available to help people orient themselves and use compasses accurately. If magnetic north is to the west of true north, this is expressed in a negative, like -15°. When it lies to the east, the declination is positive. It can be written in two different ways, with a directional symbol or a +/- symbol, as in 30E or +30. To correct for the variance, it is necessary to add or subtract to get the right measurement.

Electronic direction finding equipment can automatically correct for declination and generate an accurate true bearing. This is useful for sailors and hikers who rely on such equipment. It is important to periodically calibrate and test it to make sure it functions properly, as errors could be catastrophic. Otherwise, it is necessary to read a recent chart to determine how to correct the compass to get the right bearing. Many compasses are adjustable to allow people to correct for declination before they take a directional sighting.

Astronomers use declination to fix items on the celestial sphere relative to the celestial equator. If something is north of the equator it has a positive reading, while items south are negative. The projected south pole, for example, is located at -90° on the celestial sphere. This coordinate system allows astronomers to precisely observe and report stars and other phenomena. This acts much like latitude on Earth to determine where items are in relation to the imaginary line drawn at the equator.

WiseGeek is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Mary McMahon
By Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a WiseGeek researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Discussion Comments

Mary McMahon

Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a...

Learn more
WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.

WiseGeek, in your inbox

Our latest articles, guides, and more, delivered daily.