Our chickens tend to stay close. As long as there is pleanty of food where they are, it should be ok. It also depends on the number of chickens you have, with just a few they do not need as much room, but if you have 150 or so, they will most likely spread out pretty far. I do not know if I could really give a recomondation without seeing the situation, but you could try letting them out one day and just watch them to see what they do.
i have a 2.5 acre pasture behind our house. i will have 6-8 chickens in a chicken tractor, but i thought it would be fun for them to roam the pasture. i will let them in my fenced in back yard with the dog and kids.
We have 3 acres and my inlaws live next door with 2 and my girls generally stay on our land and their land - as my mother in law likes to feed the girls treats. everyone in a while we catch them walking down the driveway to the church p/l but they usually stay under the trees that seperate our driveay and the lot .
I have 35 (mostly bantams) on 4 acres--they manage to range over the whole property over the day, and my neighbors 4 acres (luckily they really enjoy the chickens). They're pretty good at staying out of the road--maybe once a month I'll hear someone honk the horn as they go by.
When I had a small flock with no rooster, the girls stay pretty close to the house. Now I have 12 hens, when the rooster was with them they'd be as far from the house as they could get (5 acres fully fenced in wire mesh). Before I knew they were wondering that far, I left the front gate open most of the time. Came home one day to find a mess of feathers just outside the gate. Fortunately, everyone was ok, but I try to keep the gate closed now. I have noticed that they don't seem to go down that lately since I locked the rooster up...
With my free range flock it depends on their mood. On some days they stay within the approx. five acres that consists of the house, fenced yard, their coop area and the garden. Other days they decide to go visit the neighbor (a 1/4 mile away and a big no-no) or even worse, the pond. The place where all the predators get water.
