Marine & Boating Calculators
Whether you are planning a weekend cruise or managing a vessel, our marine calculators help you make informed decisions on the water. Estimate fuel consumption for trip planning, determine the right anchor size for safe holding, calculate hull speed for your displacement hull, convert between nautical and statute miles, or work out monthly payments on a boat loan. All tools are free, instant, and built for boaters.
Boat Fuel Calculator
Estimate fuel consumption and costs for your boat trip.
Anchor Size Calculator
Find the right anchor weight and rode length for your boat.
Hull Speed Calculator
Calculate maximum displacement hull speed from waterline length.
Nautical Mile Converter
Convert between nautical miles, statute miles, and kilometers.
Boat Loan Calculator
Calculate monthly payments, interest, and total cost for a boat loan.
Frequently Asked Questions
How do I calculate boat fuel consumption?
Boat fuel consumption depends on engine horsepower, RPM, hull design, load, and sea conditions. A common rule of thumb for gasoline engines is GPH = HP x 0.1 at wide-open throttle. Our boat fuel calculator lets you input engine specs, cruising speed, and trip distance to estimate total fuel needed, plus a safety reserve for the return trip.
How do I determine the right anchor size?
Anchor size depends on your boat's length, displacement, and the conditions you expect to anchor in. Manufacturer sizing charts correlate boat length and weight to recommended anchor weight. Our anchor size calculator factors in boat length, weight, and wind conditions to suggest the appropriate anchor size and rode length for safe holding.
What is hull speed and can my boat exceed it?
Hull speed is the maximum efficient speed of a displacement hull, calculated as 1.34 times the square root of the waterline length in feet. Beyond this speed, the boat creates a large bow wave that requires exponentially more power to overcome. Planing hulls can exceed hull speed by rising onto the surface, but displacement hulls are generally limited to it.
How do I convert between nautical miles and regular miles?
One nautical mile equals 1.15078 statute miles or 1.852 kilometers. Nautical miles are based on the circumference of the Earth — one nautical mile equals one minute of latitude. Our nautical mile converter handles conversions between nautical miles, statute miles, and kilometers instantly.