Field Kit: Ham Radio Calc

Field Kit is the calm ham-radio calculator. Most shack utilities are busy and cramped; Field Kit is the opposite — legible type, gentle colors, and every formula explained in plain language right next to the answer.

Fourteen calculators, each with the working formula, a "How it works" note, and real-world examples:

• Frequency ↔ Wavelength (with velocity factor) • Antenna lengths — dipole, vertical, full-wave loop, 5⁄8-wave • Ohm's Law & Power — solve any two for the rest • Reactance & Resonance (LC) • RMS ↔ Peak ↔ Peak-to-peak, and power into a load • Combining resistors, capacitors, inductors • Peak Envelope Power (PEP) • Radio horizon / line-of-sight • Decibels, dBm ↔ watts • Link budget — does the path close? • SWR, return loss & mismatch loss • Coax loss for common feedlines • Beam heading & distance between grid squares • Battery run-time

Make it yours: a built-in Construction Kit reshapes the whole app — nine palettes (light and dark), accent colors, spacing, corner radius, and display options — and remembers your look. Every calculator has multiple solve-for modes and full unit pickers.

No accounts, no ads, no tracking — and no network at all. Field Kit runs entirely on your device, on or off the grid.

73 and good DX.