If you’ve ever heard runners, cyclists, or race organisers mention a “50K” distance, you might be wondering: how many miles is that exactly?

Whether you’re preparing for your first ultramarathon, tracking fitness goals, or just curious, this guide will give you a clear, quick conversion! It will break down everything you need to know about the 50K distance.

Quick Answer: 50K in Miles
Here is a quick conversion of kilometers to miles:

1 kilometre (km) = 0.621 miles

Therefore,

50 kilometres = 50 * 0.621 = 31.07 miles

So when someone says, “I’m running a 50K in miles,” it means they’re covering just over 31 miles. To view it in a different light, a traditional marathon (26.2 miles) is 5 miles shorter than a 50K. This is the reason why it is referred to as the entry-level ultramarathon distance.