Ham Radio Logging & Contest Calculators
Seven logging and contest calculators for amateur radio: Maidenhead grid square, great-circle distance and bearing, UTC converter, CW WPM timing, DXCC path distance, contest score estimator, and solar noon and grey line windows.
Maidenhead Grid Square Calculator
Converts latitude/longitude to a 4 or 6-character Maidenhead grid square, or decodes a grid square back to coordinates and centre point.
Great-Circle Distance and Beam Heading Calculator
Short-path and long-path distance and bearing between two locations. Enter coordinates or grid squares. Essential for DX antenna pointing.
UTC / Local Time Converter
Converts between UTC and local time for any UTC offset. Shows current UTC time and common contest periods in UTC.
CW Speed (WPM) Calculator
Converts between WPM and dot duration in milliseconds, dit/dah timing, and characters per minute. Based on PARIS standard (5 words/minute = 1 dit per 240ms).
DXCC Entity Distance and Band Prediction
Estimated path distance to a DXCC entity from your grid square, plus recommended bands and times for the contact based on path distance.
Contest Score Estimator
Estimates final contest score from QSO rate, multiplier count, and contest scoring rules. Useful for planning operating strategy.
Solar Noon, Sunrise, and Grey Line Calculator
Sunrise, sunset, solar noon, and grey line windows for any location and date. Grey line openings are prime DX opportunities on lower HF bands.