Dipole Calculator

Our dipole calculator is a simple tool that allows you to compute the length of a simple antenna — it'll also provide you with the value of the wavelength and the adjustment factor [k].

In the text below, we will cover the basic rules of antenna construction, how to calculate dipole antenna length, and explain how to put our wire antenna calculator to work.

In order to use our antenna calculator, you'll need to know the frequency on which you want your antenna to operate.

Your result will consist of:

• Your total antenna length (L);
• Length of one arm of the antenna (l); and
• Wavelength, as well as its portions: 1/2, 1/4 (it'll also allow you to use it as a 1/2 wave dipole calculator).

After this, you can also calculate the adjustment factor (k). You may need it for high frequencies and thick wires or if your antenna is made out of a tube. To calculate this, follow these steps:

1. Click on the "Adjustment factor" section at the bottom to open it.
2. Enter the value of the diameter of the dipole conductor.
3. Our calculator will instantly give you the adjustment factor!

Our wire gauge tool assesses the properties of a wire, such as its diameter and resistance 📎 — feel free to try it!

The antenna length formulas used in our dipole length calculator are as follows:

L = 468 / f

l = L / 2

where:

• L — the length of the total dipole antenna in feet (ft);
• l — the length of the arm of the dipole antenna in feet (ft); and
• f — the desired frequency.

We also used the simple wavelength formula:

Wavelength = c / f

where:

• c — the speed of light: 299,792,458 m/s; and
• f — frequency.

If you want to use the adjustment factor [k], you'll need the following version:

L = 0.5 × k × c / f

where:

• k — Adjustment factor, calculated with the following equation (simplified version):

  k = 0.9787 − [(11.86497 / (1 + (R/0.000449)^1.7925)^0.3)]

  where:

  • R = ½ wavelength / Diameter of a conductor

Dipole antennas are the easiest and probably the cheapest antennas to construct. They can give you a great insight into how antennas work and can be an excellent start for a beginner.

What will I need?

• Some wire — usually made out of copper;

• Insulators — should be placed on both ends of the wire;

• A dipole centerpiece (an insulator can serve this purpose);

• … with a feeder attached to it — usually a coax cable with an impedance of 50 Ω (remember to seal the endings!);

• Fixings;

• Two high-located, obstruction-free points to plant the antenna — the dipole's length is the most crucial feature to consider; and

• Of course — our simple dipole calculator to assess the length of the device.

It is recommended to cut the wire a little bit longer than calculated and then trim it to the length that provides you with the best results.