If Odysseus had just walked home from Troy to Ithaca; how long would it have taken him?

Let's see... Troy has been discovered over the modern Turkish town "Hisarlic" so if we calculate the distances...

From Hisarlic to Constantinopole 370 km
From Constantinopole to Thessaloniki 826 km
From Thessaloniki to Leykada 450 km

From the Leykada which is the island next to Ithaca he had to swim or take the ferry... so we can assume that he would need aproximately 1700 km by walking.

A person can walk averagely 7 km an hour with a slow pace. so Ulysses/Odysseus would need 1700 / 7 = 242 hours without a rest.

This map has the land distance between Troy/Ithaca, somewhere around 500 miles.

http://www.smithsonianmag.com/history/we-followed-odysseus-49839113/

The average person walks around 3mph...a brisker walk will average out to 4mph.

http://www.bellaonline.com/articles/art20257.asp

500 divided by 4mph...125 hours...and at 12 hours a day...around 10.5 days.

Real distances between Greek cities in km.
http://www.athensinfoguide.com/gettingarounddisgeneral.htm

Troy was discovered in Hisarlic.
https://en.wikipedia.org/wiki/Troy

Located exactly 370km from Instabul.

Zbeckabee's above link about walking is correct but you can not calculate geographical distances in "a direct line."

1700 km is about 1000 miles.