Marathon Distances Explained: 5K, 10K, Half, Full

Tap a distance to see its character.

5K (5km)

The most approachable distance for beginners, and a popular first goal for people just starting to run.

10K (10km)

A common next step for runners who've completed a 5K, requiring a bit more endurance and pacing.

Half Marathon (21.0975km)

Half the distance of a full marathon, and a popular race distance for runners beginning serious marathon training.

Full Marathon (42.195km)

The official distance, said to originate from the legend of the ancient Greek soldier Pheidippides running to Athens to announce victory at the Battle of Marathon.

Ultramarathon (over 42.195km)

A catch-all term for any distance longer than a full marathon, ranging from 50km and 100km up to extreme endurance events of 100 miles (about 161km).

Running Rewards Setting Goals in Stages

Rather than jumping straight into a full marathon, training by gradually working up through 5K, 10K, and half marathon distances is known to reduce injury risk and improve finish rates. Start with whatever distance matches your current fitness level and build up from there.

Why 42.195km?

This seemingly odd distance traces back to legend, but it was officially standardized as the exact modern figure at the 1908 London Olympics.

Frequently Asked Questions

Why is the full marathon such an oddly specific distance β€” 42.195km?

It's said to originate from the legend of the ancient Greek Battle of Marathon, and was later officially standardized to its current exact distance at the 1908 London Olympics.

How much training does it take to finish a half marathon?

It varies by individual, but someone who can already run 5K and 10K consistently often aims to finish a half marathon after around 8-12 weeks of structured training.