Yagi-Uda Antenna Calculator

This online calculator designs Yagi-Uda antennas by computing element lengths, spacings, and feed impedance for a given frequency and element count. It serves amateur radio operators, RF hobbyists, educators, and small RF design teams seeking repeatable dimensions and predictable performance. Users provide a target frequency and the number of directors (plus a reflector in standard configurations); the tool returns a complete geometry and estimated electrical parameters for construction.
Conceptually, the tool applies established Yagi design rules. The driven element is near lambda/2, the reflector is slightly longer, and directors are progressively shorter. The frequency is converted to wavelength and element lengths and inter-element spacings are derived in meters. Outputs include the predicted 50-ohm feed impedance, gain in dBi, and front-to-back ratio for the specified configuration.
Core features include required inputs (frequency and element count) and optional advanced parameters (boom length, element thickness, and matching approach). The calculator validates values, performs the design calculations, and presents per-element lengths, spacings, the total boom length, and impedance estimates. It supports side-by-side comparisons of configurations and can export a dimensions list suitable for fabrication planning.
Unique value comes from domain-focused equations, standard design tables, and built-in sanity checks that align with common amateur designs. The tool accelerates design iterations, supports field deployment planning, and aids education by illustrating how dimension changes affect impedance and gain.