A 4 watt CB radio will transmit about 1-2 miles under ideal conditions. However, in most real world situations, the range will be significantly less than that. Factors such as terrain, foliage, buildings, and other obstacles can all impact the range of a CB radio. In general, you can expect a 4 watt CB to have a range of about 0.5-1 mile in urban environments and up to 2-3 miles in rural areas with few obstructions.