Water Sports Calculators
Water sports calculators for swimmers, divers, anglers, sailors, and kitesurfers. Estimate fish weight, convert swim times, calculate hull speed, and find the right kite size.
All water sports calculators
Fishing Reel Line Capacity Calculator
Calculate fishing reel line capacity and backing needed for your target line weight.
Fish Weight Calculator
Estimate fish weight from length and girth measurements without a scale.
Hull Speed Calculator
Calculate hull speed (maximum displacement speed) from waterline length.
Kiteboarding Calculator
Find the right kite size for your weight and wind speed conditions.
Scuba Weight Calculator
Calculate required diving weights for proper buoyancy based on body weight and wetsuit.
Swim Time Converter
Convert swim times between pool distances (25m, 25y, 50m) and open water.
Windsurfing Calculator
Choose the right windsurf sail size for your weight and wind conditions.
Frequently asked questions
A:Use the length-girth formula: Weight ≈ (Length × Girth²) / 800 for most bass species. Our calculator handles multiple species.
A:Hull speed is the theoretical maximum displacement speed of a hull, approximately 1.34 × √(waterline length in feet) in knots.