Sailing Calculators

Sailboat Capsize Screen Factor Calculator

Calculate the offshore capsize screening factor for any monohull sailboat from beam and displacement. Boats under 2.0 are considered offshore-capable by ORC standards.

Sail Trim by Point of Sail Calculator

Get sail trim angle and traveler position for any point of sail. Reference table for close-hauled, beam reach, broad reach, and run with twist guidance.

Sailing Velocity Made Good (VMG) Calculator

Calculate sailing VMG to windward or leeward by boat speed and wind angle. Find optimal pointing angle and tacking strategy for upwind and downwind legs.

Anchor Scope Calculator

Calculate how much anchor chain or rope to let out based on water depth, boat freeboard, and weather conditions. Stay safe at anchor.

Apparent Wind Calculator

Calculate apparent wind speed and angle from true wind speed, true wind angle, and boat speed. Essential for sail trim and racing tactics.

Boat Fuel Range Calculator

Calculate your cruising range and engine endurance from tank capacity, fuel consumption, and speed. Includes safety reserve calculation.

Course to Steer Calculator

Calculate the compass heading to steer to counteract tidal current and leeway. Find the actual course made good and estimated speed over ground.

Hull Speed Calculator

Calculate the theoretical hull speed of a displacement boat from waterline length. See the Froude number threshold and power required to exceed hull speed.

Mast Rake Calculator

Calculate mast rake angle from mast height and horizontal offset. Helps optimize helm balance by adjusting rake forward or aft on dinghies and keelboats.

Sail Area Calculator

Calculate total sail area for a sloop rig (mainsail + jib). Compute sail area-to-displacement ratio to assess boat performance.

Sailboat Heeling Angle Calculator

Estimate a sailboat heeling angle from wind pressure and righting moment. Understand the stability trade-off for different sail configurations.

Sailing Dead Reckoning Calculator

Calculate distance, speed, or time for boat passage planning. Solve for any variable using the fundamental D = S x T formula in nautical miles and knots.

Sailing Handicap Calculator (Portsmouth Yardstick)

Calculate corrected time for handicap sailing races using the Portsmouth Yardstick (PY) system. Compare two boats to find the race winner on corrected time.

Tidal Current Speed Calculator

Estimate tidal current speed at any point in the tidal cycle using the 50/90 rule. Enter max current speed and time before or after slack water in hours.

Tidal Height Calculator

Estimate the height of tide at any time between high and low water using the 1/12 rule. Find out if there is enough depth to enter a harbour or anchorage.