For many people, just the thought of running a marathon will make you feel exhausted. It’s often seen as one of the most challenging events a person can do since it forces you to push yourself both physically and mentally.

From start to finish, it is a 26.2 miles long race, a feat that takes intense training and preparation to finish. It’s certainly not something you should be doing on a whim.

But why is it 26.2 miles, and how much is that in kilometers? Where did this number originate from? That’s what we’ll dive into in this article.

We’ll explore how many kilometers (km) are in a marathon, how to convert any distance between miles and kilometers, the history of the marathon race, and much more.

A marathon is 42.195 kilometers long. Typically, we speak of the official marathon distance in miles, which makes a marathon race 26.2 miles long – 26 miles and 385 yards, to be exact. But, when the marathon metric is converted from miles to kilometres, it equates to 42.195 km.

As a general rule of thumb, 1 mile equals 1.6 km. Or, if you want to convert kilometers to miles, 1 km equals 0.62 miles. These quick conversions can help you convert the length of any distance into a metric you’re familiar with or you can use our unit conversion calculator.

Although the length of a full marathon is now standardized at 26.2 miles, it wasn’t always the case. In fact, the first marathon races were 25 miles long. The change happened at the 1908 Olympics, which were held in London, and involved the British Royal family.

The Queen of the United Kingdom, Queen Alexandra, had requested that the marathon begin on Windsor Castle’s lawn. This was so that her children, who were young then, could see the start of the race from their rooms. She also requested the finish line to be in front of the royal box at the Olympic Stadium. These requests were granted but meant that a marathon runner would have to run 26 miles and 385 yards instead of 25 miles, as that was the measured distance between both locations.

Instead of reverting back to the usual 25-mile marathon course at the next Olympic games, the new distance remained. It was then standardized in 1921, which meant that it became the official distance of all Olympic marathon races going forward.

Using the conversion rate mentioned earlier, we can change any distance from miles to kilometers and back. To refresh your memory, 1 mile equals 1.6 km, and 1 km equals 0.62 miles. Knowing this, let’s convert a few race distances to see this in practice.

A 5K race (5 km) would equate to 3.1 miles (0.62 km multiplied by 5)

A 10k race (10 km) would equate to 6.2 miles (0.62 km multiplied by 10)

A 15k race (15 km) would equate to 9.3 miles (0.62km multiplied by 15)

A half marathon is exactly half the distance of a full marathon. With a marathon being 26.2 miles long, a half marathon is 13.1 miles long, or 21.0975 km.

The term ‘ultramarathon’ is given to any race that is longer than the distance of a full marathon (26.2 miles). Usually, ultramarathons are set in multiples of 50 miles or kilometers. For instance, 50 miles, 100 miles, and 150 miles, or 50 km, 100 km, and 150 km.

The world’s longest certified ultramarathon is the Self-Transcendence marathon, with a distance of 3,100 miles. The foot race takes place in New York every summer and is the longest sanctioned marathon worldwide. The runners have a time limit of 52 days to finish the race and can only run between 6 am and midnight each day.

It’s a common myth that the first marathon race was held during the first few Olympic games. Although there were sprinting and other running events, there wasn’t a long-distance marathon-style race as we know it.

However, the marathon’s history does start in Ancient Greece with a Greek soldier by the name of Philippides, also known as Pheidippides. He was a soldier in the Greek army and was said to have run from a battle in Marathon to Athens without stopping to deliver the message of victory. The distance between these two places was 25 miles. He soon died after the trip as a result of exhaustion, which is said to have been compounded by a 150-mile march in the days leading up to his 25-mile run.

It wasn’t until the Olympic games of the modern era in 1986 that we saw the first Olympic marathon. The organizers wished to include a long-distance race in the Olympic games in honor of Philippides’ feat. It was organized as a 25-mile-long race, the same distance that Philippides ran from Marathon to Athens.

The following year in 1987, the Boston Marathon was organized. It is the world’s oldest annual marathon and still runs to this day, making it one of the most prestigious events for marathon runners.

As we mentioned earlier, the distance of the Olympic games marathon was then extended to 26.2 miles at the request of Queen Alexandra of Britain in 1908, which has now been standardized globally.

This depends on whether you are an Olympic-level athlete competing in marathon races or if you are an ‘average joe’ who runs as a hobby.

According to a 2019 study, the average marathon time for a male is 4 hours and 21 minutes, and the average time for a women’s marathon is 4 hours and 48 minutes. The average marathon time worldwide for all participants is 4 hours and 29 minutes, hence why a time between four hours and five hours is considered to be a good time; anything under four hours is considered to be a great time that not many can achieve.

When it comes to professional marathon runners, it’s a different story. The current world record for male participants is held by Kenyan international Eliud Kipchoge, who ran a time of 2:01:39 at the Berlin Marathon in 2018. Interestingly, the women’s world record is also held by a Kenyan international, Brigid Kosgei. She ran a time of 2:14:04 at the Chicago Marathon in 2019.

As you can see, a seasoned runner can run a marathon in half the time as the average person. Only the top five percent of runners can run marathons in under three hours, and even fewer can do it in less than two and a half hours.

There are six major marathon races in the world, known as the World Marathon Majors. It’s a championship-style competition that began in 2006 that involves the most high-profile marathon races in the world. It consists of the Tokyo Marathon, Boston Marathon, Berlin Marathon, London Marathon, Chicago Marathon, and New York Marathon.

A full marathon is 26 miles and 385 yards long, which is 41.195 kilometers. Marathons used to have a distance of 25 miles, but this was changed at the 1908 Olympics at the request of the Queen. It then became the standardized distance for all marathons going forward.