Dipole Antenna Calculator

Dipole antenna calculator: estimate idealized half-wave and arm lengths from frequency and your velocity factor. Enter a frequency and your own velocity factor, then read the clearly labeled diagram and results.

A USEFUL FREE CALCULATOR
Use Hz, kHz, MHz or GHz. Switch between metres, centimetres, decimal feet and feet with inches. See the formula and assumptions, choose a light or dark theme, and keep your calculator inputs across restarts. Core calculations work offline without an account or advertising.

LIFETIME PRO FOR REPEATED BUILDS
The optional one-time upgrade adds creation, editing and duplication of saved band profiles, build notes, and ordered comparisons of 2-12 frequencies. Keep each comparison's frequency and factor snapshots together. Preview text notes and CSV worksheets before saving or sharing. Export a JSON backup through Android's document picker.

Existing records remain readable, exportable, deletable and recoverable in Free. Import restores worksheet records, never purchase ownership. Pro is a lifetime upgrade, not a subscription. Purchase availability and the local price come from Google Play. Restore a purchase with the owning Play account online.

KNOW THE MODEL
The app uses c = 299792458 m/s and your explicit factor. The half-wave result is the total conductor length; each equal arm is the quarter-wave result. These are idealized dimensions. Construction, end effects and surroundings can change actual resonance. The app does not determine SWR, impedance, gain, propagation, RF exposure, regulatory compliance or a tuned construction result.

LOCAL WORKSHEETS, EXPLICIT EXPORTS
Records stay on your device unless you choose to export or share them. Google processes purchase services and related Billing diagnostics. Automatic Android cloud backup is disabled. Keep your own JSON backup before uninstalling or clearing storage.

Support: [email protected]

If Amateur Radio Toolkit is already part of your hobby routine, use this separate antenna length calculator to inspect idealized dimensions in metres or feet. For a ham radio antenna project, enter the frequency and your chosen velocity factor, then check how the total conductor length divides into two equal arms.