What is windage area?
Windage area is the projected area of the ship above the waterline that the wind can push against. High-sided ships such as container vessels, car carriers and cruise ships have a large lateral windage. That extra area increases berth loads, makes the ship harder to handle at slow speed, and can cause leeway when approaching a lock or canal.
How this calculator works
Area = Exposed length × Exposed height. Approximate wind force uses F = 0.5 × air density × V² × Area × Cd, with wind speed converted from knots to metres per second. Air density is taken as 1.225 kg/m³. The result is shown in kN and tonnes-force. This is a first estimate only. Official mooring and canal calculations use more detailed area breakdowns from the ship’s general arrangement.
Who should use it
Useful for officers thinking about wind effect during berthing or anchoring. Always combine this with current, underkeel clearance and tug availability. Do not treat the force figure as an exact engineering value.