Useful calculators brings together quick onboard navigation maths. Access: Tools → Useful calculators.
Available calculators
- Reverse azimuth
Enter the initial bearing (0–360°) — the app calculates the return course (bearing + 180°) with a cardinal direction label.
- Time – distance – speed
Fill exactly two fields (distance in nautical miles, speed in knots, time in hours) — the third is calculated automatically. Formula: distance [nm] = speed [kn] × time [h].
- Kilometres, nautical miles and knots
Unit converter for distance (nm, km, m) and speed (knots, km/h, m/s). Select the source unit and enter a value.
- Fuel consumption and range
From fuel on board [l], consumption [l/h] at a given cruise speed [kn], calculates engine endurance, range in nautical miles and litres per mile. Optionally enter planned distance [nm] to estimate fuel required.
- Distance between coordinates
Two points (latitude and longitude) — result: distance (nm and km), initial bearing and reverse azimuth. Coordinates can be entered as decimal degrees or DMS (e.g. N 54° 21' 07"). “Use current GPS position” fills point A from GPS.
- Coordinate conversion
From DD position (or after decoding UTM/MGRS) shows: decimal format, DMS, DDM, UTM and MGRS (WGS84). You can enter UTM (e.g. 34N 347054 6025240) or MGRS (e.g. 34UCF 47054 25240) to decode them.
- Magnetic declination correction
From GPS position and date shows magnetic declination (WMM model). Enter magnetic or true bearing — the other is calculated using declination (east positive).