Boating
Free boating calculators: boat trim, fuel consumption, hull speed, anchor sizing, prop pitch, engine horsepower, and towing guides.
Boat Propeller Slip Calculator
Calculate propeller slip percentage from theoretical and actual boat speed. A useful diagnostic for identifying prop pitch mismatch or hull fouling.
Boat Trailer GVWR Calculator
Calculate the minimum trailer GVWR rating for any boat from dry weight, motor, fuel, gear, and trailer weight. Avoid an overloaded trailer.
Boat Engine Hours Service Schedule Calculator
Project boat engine maintenance from total hours and run rate. Get next oil change, impeller, gear lube, and major service intervals with cost estimates.
Boat Bottom Paint Calculator
Estimate gallons of antifouling paint needed for your boat hull. Calculated from waterline length, beam, and draft with coverage rate and number of coats.
Boat Trailer Towing Calculator
Check if your vehicle can safely tow your boat and trailer. Calculate combined weight, tongue weight, and whether your setup meets towing capacity limits.
Marine Battery Bank Calculator
Size your boat battery bank from daily amp-hour usage. Enter electrical loads and reserve days to find the capacity and number of batteries needed.
Boat Displacement Calculator
Calculate boat displacement in pounds and tons, waterline length, and D/L ratio. Classifies your vessel as ultralight, light, moderate, or heavy displacement.
Boat Draft Calculator
Calculate your boat's draft from hull type, displacement, and current load. Find minimum safe water depth for coastal navigation and tidal waterway planning.
Boat Fuel Range Calculator
Calculate boat range on a full tank from engine type, cruising speed, burn rate, and capacity. Applies the one-third rule for safe offshore planning.
Boat Propeller Size Calculator
Calculate the right propeller pitch and diameter for your boat and engine. Optimize for top speed, fuel efficiency, or load carrying using RPM and gear ratio.
Anchor Chain Length Calculator
Calculate anchor rode and chain length from water depth using the 7:1 scope rule. Covers calm, moderate, and storm conditions with chain minimums by boat size.
Boat Trim Calculator
Calculate boat trim angle and weight distribution from forward and aft draft measurements. Includes ideal trim ranges by boat type.