John Napier: Biography, Logarithms & Facts

Instructor: Betsy Chesnutt

Betsy teaches college physics, biology, and engineering and has a Ph.D. in Biomedical Engineering

John Napier was a Scottish theologian and mathematician who is most famous for inventing one of the most powerful mathematical tools in existence, the logarithm. In this lesson, learn about his life and his most famous invention!

A Problem in Mathematics

Today, if you want to perform any mathematical calculation, you probably just use a calculator, right? Calculators are easy to use and widely available, and they make it simple to perform even the most complex calculations. However, back in the sixteenth century, there were no calculators! Every calculation had to be done by hand, and this could be pretty difficult and tedious. The inability to perform accurate calculations seriously limited scientific research in many fields.

However, things were about to improve. In 1550, a man named John Napier was born in Scotland. By the end of the century, he had revolutionized mathematics and science by making it much easier to perform certain types of very difficult calculations. What was this remarkable new tool he invented? He called it the logarithm.

Who Was John Napier?

The early life of John Napier is shrouded in mystery. He was born in 1550 in Merchiston Castle in Scotland and grew up as the son of a prominent land owner. He was educated at home until he was thirteen, and then he enrolled in St. Andrews University. He didn't stay there long though and left before graduating. There aren't good records of where he went after that, but it is believed that he went spent time studying in Paris, as well as Italy and the Netherlands. Finally, he returned to Scotland in 1571 at the age of 21. He married Elizabeth Stirling the next year, and they had two children. After her death in 1579, he married again and had ten more children with his second wife, Agnes Chisholm.

John Napier was a Scottish mathematician who is famous for the invention of logarithms.
John Napier was a Scottish mathematician who is famous for the invention of logarithms.

Napier was many things, including a Protestant theologian and a prominent member of the Scottish landed gentry. However, he was NOT a professional mathematician. Instead, be mainly pursued the study of mathematics as a hobby in his free time. Even as a part-time mathematician, he was able to make some pretty big contributions!

Invention of Logarithms

Napier spent a lot of his free time studying mathematics. He was particularly interested in developing methods to make complex calculations easier. He invented several new devices and techniques that assisted mathematicians in performing difficult calculations, including a way to multiply and divide numbers using a series of small rods known as Napier's bones. This was an early precursor of the slide rule, which generations of scientists, mathematicians, and engineers would later rely on.

Napier also popularized the use of decimals, which were not commonly used before Napier's time. However, he is most famous for the invention of logarithms. A logarithm is the exponent to which a number called the base must be raised in order to give a specific value. Logarithms greatly simplified many types of calculations, especially those involving multiplying very large numbers. After their invention by Napier in the early 1600s, they were used extensively for more than 300 years. They are used much less commonly today for calculations since calculators and computers are even faster and more accurate

In this pivotal book, John Napier first introduced the concept of logarithms.
In this pivotal book, John Napier first introduced the concept of logarithms.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account