This calculator compares expected radio communication distances using:

• Ground Wave: travels along Earth's surface, especially at lower HF and MF bands
• Sky Wave: reflects off the ionosphere and enables long-distance DX contacts

Ground wave range depends heavily on frequency, terrain, ground conductivity, and power. Lower frequencies (e.g. 160m) follow ground better than higher bands.

Sky wave (ionospheric) range depends on ionospheric layer reflection:

• E-layer: shorter hops (~600–1200 km)
• F2-layer: long-distance skip (~2000–4000+ km)

Use this tool to estimate how far your signal might go under average conditions. It's useful for NVIS planning, nighttime 40m operation, or long-haul HF DX work.