14. How long would it take you to run around the world? Hence, Earth circumference is 2*Pi*r is about 40,030 km. Now is up to you to decide the amount of running per day. If you run a marathon 42.2 km per day, you'll be done in around 2.5 years.

14. How long would it take you to run around the world?

Hence, Earth circumference is 2*Pi*r is about 40,030 km. Now is up to you to decide the amount of running per day. If you run a marathon 42.2 km per day, you'll be done in around 2.5 years.