Professional Marine Calculators
Free tools for hull speed, navigation, anchor scope, fuel range, and boat systems. Built for boaters, sailors, and marine professionals.
Performance & Speed
Calculate vessel performance, fuel efficiency, and range
Hull Speed Calculator
Calculate theoretical maximum hull speed and speed/length ratio for displacement vessels.
Fuel & Range Calculator
Estimate fuel consumption, range, and endurance based on engine parameters.
Fuel Consumption Calculator
Calculate fuel usage at different speeds and plan for voyage fuel requirements.
Displacement Calculator
Calculate vessel displacement from dimensions and block coefficient.
Navigation
Route planning, position calculations, and course corrections
Distance & Bearing
Calculate great circle distance and initial bearing between two coordinates.
Coordinate Converter
Convert between decimal degrees and degrees/minutes/seconds formats.
ETA Calculator
Calculate estimated time of arrival based on distance and speed.
Magnetic Deviation
Calculate compass deviation and convert between true and magnetic bearings.
Tidal Current Calculator
Calculate current effects on course and speed for accurate navigation.
Anchoring & Ground Tackle
Safe anchoring calculations and equipment sizing
Anchor Scope Calculator
Calculate required rode length based on depth, freeboard, and conditions.
Anchor Chain Sizing
Select proper chain size based on boat length and displacement.
Chain Weight Calculator
Calculate anchor chain weight for different sizes and lengths.
Swing Radius Calculator
Determine anchor swing circle for safe clearance planning.
Weather & Wind
Wind and weather calculations for sailors
Boat Systems
Electrical, water, and mechanical system calculations
Battery Bank Calculator
Size battery banks based on power consumption and autonomy requirements.
Solar Charging Calculator
Calculate solar panel requirements for marine battery charging.
Bilge Pump Sizing
Size bilge pumps based on boat size and safety requirements.
Watermaker Calculator
Size watermakers based on crew size and daily water consumption.
Reference Tables
Quick reference guides and nautical data
Why Use Our Calculators?
Works Offline
Install as PWA. All calculations run locally in your browser.
USCG Standards
Based on Coast Guard requirements and industry standards.
No Login Required
Start calculating immediately. No account needed.
Mobile Friendly
Use on phone, tablet, or laptop while on the water.