SEA Calculator

SEA Calculator is a professional suite of marine navigation calculators for seafarers, masters, and deck officers. All tools work offline — no registration and no ads.

CALCULATORS:
• ETA — estimated time of arrival from distance, speed, and time zones (UTC-12 to UTC+14); speed/ETA table, time to go (TTG), display in local time and GMT
• Speed — required speed to arrive at a given time
• Fuel — fuel consumption (ME/AE) from distance and speed
• True Wind — true wind speed and direction from course, ship speed, and relative wind
• Dates — number of days between two dates
• Time — difference between two date/time values
• Interpolation — linear interpolation for ship tables
• ASTM D4311 — volume correction factor (VCF) for asphalt
• UTI — zero correction (Zc) calibration
• Unit Converter — physical units (acceleration, area, density, temperature, pressure, mass, flow, and more)

ALSO INCLUDED:
• History of up to 50 recent calculations with filter and sort
• Light and dark theme
• Auto-save of entered values
• Show/hide individual calculators
• Mobile-friendly interface

SEA Calculator is intended for professional marine calculations and does not replace official ship navigation systems.