While a standard 5 watt two way radio can easily achieve a range of 3 to 10 kilometres (or more) in open conditions, there is no single, fixed distance.
Your actual range depends entirely on three factors:
Terrain and environment: Open fields allow signals to travel much further than dense urban city centres.
Building materials: Reinforced concrete and steel will compress a signal more than brick or timber.
Radio setup: Upgrading to a digital network or installing an on-site repeater can extend your coverage over massive industrial zones or multi-storey properties.