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Antenna Frequency Calculator

Convert between frequency and wavelength. Calculate quarter-wave and half-wave antenna lengths.

Common frequency bands reference
AM Radio 535 kHz – 1.7 MHz
FM Radio 87.5 – 108 MHz
ADS-B (aviation) 1090 MHz
L-Band GPS 1.2 – 1.6 GHz
2.4 GHz Wi-Fi / BT 2.4 – 2.5 GHz
5 GHz Wi-Fi 5.15 – 5.85 GHz
GSM 900 880 – 960 MHz
LTE Band 1 1.9 – 2.2 GHz
DVB-T (TV) 174 – 862 MHz
NOAA Weather Sat 137.1 – 137.9 MHz
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How to use the antenna calculator

Enter a frequency (e.g. 433.92 MHz for LoRa/433 ISM band) and the calculator instantly shows the full wavelength plus the ideal antenna lengths for a half-wave dipole and quarter-wave monopole.

Formula

Wavelength (λ) = Speed of Light (c) / Frequency (f), where c ≈ 299,792,458 m/s. Antenna length = λ / 4 for monopole, λ / 2 for dipole.

Common SDR use-cases

  • RTL-SDR antenna cutting for a specific frequency
  • LoRa 433/868/915 MHz antennas
  • NOAA weather satellite (137 MHz)
  • ADS-B aircraft tracking (1090 MHz)
  • GPS L1 (1575.42 MHz)