Yagi-Uda Antenna Element Planner
Give a frequency, a number of directors and a boom profile, and get every element length and its position along the boom. Conventional starting dimensions for trimming on the bench; the calculation runs entirely in your browser.
Element lengths are conventional fractions of a free-space wavelength for thin elements, taken from typical short, standard and long-boom Yagi designs: the reflector runs about 5% longer than the driven element and each director is trimmed slightly shorter down the boom. Thicker elements, insulated mountings, a balun and nearby metal all move the tuning point, so cut a little long and trim with an SWR meter or analyser. These are starting dimensions, not an optimised or simulated design; boom length in wavelengths is the number to compare with published gain tables. Nothing is stored and the page makes no network requests.