Water Ski Size Calculator

Water Ski Size Calculator

Imperial (lbs / mph) Metric (kg / kph)

Recommended Ski Length:

function toggleUnits() { var unit = document.getElementById("unitSystem").value; var weightLabel = document.getElementById("weightLabel"); var speedLabel = document.getElementById("speedLabel"); if (unit === "imperial") { weightLabel.innerHTML = "Skier Weight (lbs)"; speedLabel.innerHTML = "Target Boat Speed (mph)"; } else { weightLabel.innerHTML = "Skier Weight (kg)"; speedLabel.innerHTML = "Target Boat Speed (kph)"; } } function calculateSkiSize() { var weight = parseFloat(document.getElementById("skierWeight").value); var speed = parseFloat(document.getElementById("skiingSpeed").value); var unit = document.getElementById("unitSystem").value; var resultDiv = document.getElementById("resultArea"); var sizeDisplay = document.getElementById("recommendedSize"); var adviceDisplay = document.getElementById("sizeAdvice"); if (isNaN(weight) || isNaN(speed) || weight <= 0 || speed <= 0) { alert("Please enter valid weight and speed values."); return; } // Convert to Imperial for internal logic var calcWeight = (unit === "metric") ? weight * 2.20462 : weight; var calcSpeed = (unit === "metric") ? speed * 0.621371 : speed; var baseLength = 0; // Slalom Sizing Logic (Base Weight) if (calcWeight = 110 && calcWeight = 135 && calcWeight = 160 && calcWeight = 185 && calcWeight = 210 && calcWeight < 240) { baseLength = 69; } else { baseLength = 71; } // Speed Adjustments // If skiing very slow, you need more surface area (longer ski) if (calcSpeed = 26 && calcSpeed 34) { baseLength -= 1; adviceDisplay.innerHTML = "Higher speeds allow for a shorter ski, providing more agility in the course."; } else { adviceDisplay.innerHTML = "This size provides a perfect balance of stability and performance."; } resultDiv.style.display = "block"; sizeDisplay.innerHTML = baseLength + " inches (" + (baseLength * 2.54).toFixed(1) + " cm)"; }

How to Choose the Right Water Ski Size

Choosing the correct water ski size is the most critical decision for any skier, whether you are just learning to get out of the water or carving up a slalom course. A ski that is too small will sink and make deep-water starts difficult, while a ski that is too large will feel sluggish and hard to turn.

Key Factors in Water Ski Sizing

There are three primary variables that determine the length of the ski you should use:

• Skier Weight: This is the most important factor. Heavier skiers require more surface area (longer and wider skis) to stay on top of the water.
• Boat Speed: As speed increases, the water provides more lift. If you ski at high speeds (34-36 mph), you can use a shorter ski. If you prefer slower speeds (26-30 mph), you need more ski length to compensate for the lack of lift.
• Ski Style: Slalom skis (single) are generally sized differently than combo skis (pair). This calculator focuses on Slalom sizing, which requires precise fitment.

Slalom Ski Size Chart (General Reference)

Weight Range (lbs)	Length (Inches)
Under 110 lbs	63″ – 64″
110 – 135 lbs	64″ – 65″
135 – 160 lbs	65″ – 66″
160 – 185 lbs	66″ – 67″
185 – 210 lbs	67″ – 68″
Over 210 lbs	69″ – 71″

Understanding Speed and Lift

If you are an aggressive skier who enjoys high-speed turns, the physics of water tension allows you to utilize a shorter ski. The shorter length reduces the "swing weight," making the ski more maneuverable. Conversely, beginners or recreational skiers often prefer speeds below 30 mph. For these users, we recommend "sizing up" one bracket to ensure the ski doesn't "dig in" or stall during turns.

Frequently Asked Questions

What happens if I use a ski that is too small?

A ski that is too small will sit too deep in the water. This creates excessive drag, which tires out the skier's arms and makes it very difficult to maintain balance during turns.

Should I choose a wide-body ski?

Wide-body skis provide more surface area without adding length. These are excellent for beginners and those who want to ski at very slow speeds (18-24 mph) or have difficulty with deep-water starts.