Use this nautical calculation for a transparent unit, speed, tide, rhumb-line, or apparent-to-true wind estimate when position, heading, current, and unit conventions are explicit.

High water

Required number input.

Low water

Required number input.

Calculate tidal range in meters as high-water height minus low-water height, using heights referenced to the same chart datum. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Tidal range

The resulting tidal range returned as a number.

• Navigation results can depend on Earth model, chart datum, magnetic variation, leeway, current, wind reference, tide station, hull form, water depth, and weather. Simplified hull-speed and rhumb-line formulas do not establish a safe passage.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Cross-check current charts, tide and weather services, vessel instruments, and approved navigation methods before operational use.

• Fathoms to Meters Converter

  Convert a depth in fathoms to meters using the exact international fathom of one point eight two eight eight meters.

• Hull Speed Calculator

  Calculate the displacement hull speed in knots from the waterline length in feet.

• Rhumb Line Distance Calculator

  Calculate the rhumb line distance in nautical miles between two geographic positions along a constant bearing.