Calculators & Tools

Wavelength ↔ Frequency Calculator

Frequency and wavelength describe the same radio signal in different ways. This calculator converts between frequency (MHz) and wavelength (meters) using the standard speed-of-light approximation commonly used throughout amateur radio. The calculator works in either direction — enter either a frequency or a wavelength and the corresponding value will be calculated automatically.

Enter frequency or wavelength
MHz
m
Formula Reference
Frequency to Wavelengthλ (m) = 300 ÷ f (MHz)Wavelength in meters equals 300 divided by frequency in MHz
Wavelength to Frequencyf (MHz) = 300 ÷ λ (m)Frequency in MHz equals 300 divided by wavelength in meters

The constant 300 represents the approximate speed of light (300 million meters per second) and provides sufficiently accurate results for amateur radio antenna planning.

Amateur Radio Band Reference
BandFrequency (MHz)Approx. Wavelength
160 m1.8166.7 m
80 m3.585.7 m
60 m5.356.6 m
40 m7.142.3 m
30 m10.129.7 m
20 m14.221.1 m
17 m18.116.6 m
15 m21.214.2 m
12 m24.912.0 m
10 m28.410.6 m
6 m50.16.0 m
2 m1462.05 m
70 cm4460.67 m
Common Amateur Radio Applications
  • Estimating antenna element lengths
  • Understanding amateur radio band names
  • Designing portable antennas
  • Planning field deployments
  • Studying propagation
  • RF education
  • SOTA and POTA antenna construction
  • Emergency communications planning
Why Are Amateur Radio Bands Named by Wavelength?

Amateur radio bands are traditionally identified by their approximate wavelength rather than their operating frequency. For example, the 20-meter band operates near 14 MHz, while the 2-meter band operates near 146 MHz. This calculator helps illustrate the mathematical relationship between those two ways of describing the same radio signal.