How many km can a man walk a day?

That is entirely up to who is walking. a man in top shape can walk for the entire 24 hour period and cover 100+km in one day. Someone grossly out of shape or just not used to walking would be done after 1-2km.. It all depends on the person , the conditions, the terrain and the load being carried. As an example, the 50km walk can be done in under 4hrs but they are racing , a hiker carrying gear would cover average 25km a day, I do a run and walk combo for about 20km and it takes me 3 hrs but I only go in optimum weather and I wear 10 grams of clothes.. Anyone in decent shape with the right shoes and climate should be able to cover 20km a day..