Communication Range Calculator
Estimate two-way radio range for emergency communication. Compare FRS, GMRS, CB, and ham radio options for your needs.
Calculate Communication Range
Understanding Radio Communication Range
Two-way radios provide critical communication when cell networks fail. However, advertised ranges like "35 miles" rarely match reality. Actual range depends on power, terrain, antenna, and environmental factors.
Radio Service Comparison
| Service | Max Power | License | Typical Range | Cost |
|---|---|---|---|---|
| FRS | 2 watts | None | 0.5-2 miles | $20-50/pair |
| GMRS | 50 watts | $35/10 years | 1-25 miles | $50-300 |
| CB | 4 watts | None | 1-5 miles | $30-150 |
| Ham (VHF/UHF) | 50+ watts | Technician exam | 5-50+ miles | $25-500+ |
| Ham (HF) | 1500 watts | General exam | Worldwide | $500-5000+ |
Factors Affecting Range
Terrain
- Line of sight: Radio waves travel in straight lines; hills block signals
- Buildings: Walls absorb and reflect signals, reducing range by 50-90%
- Forests: Dense foliage can reduce range significantly
- Water: Signals travel well over water with minimal obstacles
Power
Doubling power only increases range by about 40%. Going from 2W to 5W matters more than 25W to 50W.
Antenna
Antenna quality and height often matter more than power. An elevated external antenna can triple range compared to a handheld rubber duck antenna.
Emergency Communication Planning
Recommended Setup
- Minimum: FRS radios for family coordination within neighborhood
- Better: GMRS with mobile unit for extended range
- Best: Ham license with VHF/UHF for community networks
GMRS Repeaters
GMRS repeaters can extend range dramatically. Check for repeaters in your area - they can turn a 5-mile handheld into a 30+ mile communication tool.
Frequently Asked Questions
Do I need a license for two-way radios?
FRS radios require no license. GMRS requires a simple $35 FCC license (no test) covering your whole family for 10 years. Ham radio requires passing a technician exam. CB radio requires no license.
Why is my radio range so much less than advertised?
Advertised ranges assume perfect conditions: flat terrain, no obstacles, elevated antennas, and maximum power. Real-world range with handheld radios in suburban areas is typically 1-5 miles for GMRS and under 2 miles for FRS.
What radios work when cell phones don't?
All two-way radios (FRS, GMRS, CB, ham) work independently of cell infrastructure. They communicate directly radio-to-radio. Ham radio operators can also use repeaters and emergency networks that operate during disasters.