Free · No sign-in
Nautical calculators
A focused set of navigation and passage-planning tools — precise, fast,
and usable on a phone at the chart table or in the cockpit. No sign-in,
no clutter, works offline.
Calculators
Distance & bearing Great-circle and rhumb-line between waypoints Speed · Time · Distance Solve any one from the other two, plus ETA Set & drift Current triangle and course-to-steer Dead reckoning Plot a DR position from course and log Tides & clearance Rule of twelfths and clearance under keel Fuel & range Burn rate, reserve, and endurance Anchor scope Rode length for depth, tide, and freeboard Distance to horizon Sighting range for lights and objects Compass conversion True, magnetic, and compass with deviation Hull speed Displacement speed limit from waterline length Apparent wind Apparent speed and angle from true wind Sunrise & sunset Daylight and civil twilight for any position Lat / long converter Decimal degrees, DDM, and DMS Unit converter Nautical miles, knots, fathoms, hPa, and more