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Calcimator

Dipole Antenna Length Calculator

Calculate half-wave dipole element length from target frequency. Includes quarter-wave, full-wave, and 5/8-wave lengths.

Inputs

MHz
%

Results

Half-Wave Dipole (Total)

3.21 ft

≈ 7 smartphones

Each Dipole Leg

1.6 ft

≈ 6 credit cards

Half-Wave Dipole (Total)0.98 m
Each Dipole Leg0.49 m
Quarter-Wave Vertical1.6 ft
Quarter-Wave Vertical0.49 m
Full Wavelength6.41 ft
5/8-Wave Vertical4.01 ft
Wavelength1.951 m
Wire Diameter1.628 mm
Full Wave M1.95
Five Eighths M1.22
How to Use This Calculator
  1. Enter your target operating frequency (MHz).
  2. Set the velocity factor (0.95 for bare wire, lower for insulated wire).
  3. Select wire gauge (AWG) -- thicker wire has slightly lower velocity factor.
  4. Review the half-wave dipole total length and each leg length in both feet and meters.
  5. Cut wire to the leg length dimension and adjust with an antenna analyzer for best VSWR.

How the result changes with Target Frequency

Target FrequencyHalf-Wave Dipole (Total)Each Dipole Leg
1,0000.47 ft0.23 ft
3,5000.13 ft0.07 ft
6,5000.07 ft0.04 ft
9,0000.05 ft0.03 ft

What each input means

Target Frequency
Center frequency for the antenna in megahertz
Velocity Factor
Wire velocity factor (bare copper wire: ~95%, insulated: ~93%)
Wire Gauge (AWG)
American Wire Gauge for antenna elements (10-14 AWG typical)

How this is calculated

Formula

Length (ft) = 468 / f(MHz)

Worked example, using the default values

  1. Identify Input Parameters
    Target Frequency = 146, Velocity Factor = 95, Wire Gauge (AWG) = 14 = 3 input(s) provided
  2. Calculate Half-Wave Dipole
    Half-Wave Dipole
    3.21 = 3.21
  3. Calculate Each Dipole Leg
    Each Dipole Leg
    1.6 = 1.6
  4. Calculate Half-Wave Dipole
    Half-Wave Dipole
    0.98 = 0.98
  5. Calculate Each Dipole Leg
    Each Dipole Leg
    0.49 = 0.49

Engine last updated . Checked against 4 independently-derived tests — how we verify calculators.

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