Slalom ski size is set by your weight and your boat speed together, not weight alone. The faster you ski, the shorter the ski you can hold, because speed generates lift. Two skiers of the same weight running different speeds belong on different length skis.
Find your weight in the chart below, then read across to the speed you actually ski at.
Slalom ski size chart by weight and speed
| Rider weight | Ski at 46 to 49 km/h (29 to 30 mph) | Ski at 50 to 55 km/h (31 to 34 mph) | Ski at 56 km/h and up (35 mph +) |
|---|---|---|---|
| Under 45 kg | 61 to 63 in | 61 in | 61 in |
| 45 to 57 kg | 63 to 65 in | 63 in | 63 in |
| 57 to 68 kg | 65 to 66 in | 65 in | 65 in |
| 68 to 80 kg | 67 in | 66 in | 65 to 66 in |
| 80 to 91 kg | 68 in | 67 in | 66 in |
| 91 to 100 kg | 69 in | 68 in | 67 in |
| Over 100 kg | 71 in | 69 to 71 in | 69 in |
Ski lengths are quoted in inches, and always have been. Charts vary between brands, so confirm against the chart on the ski you are buying.
If you are between sizes, go longer. A longer ski is more stable, easier to get up on and more forgiving of a bad turn. A ski that is too short simply sinks at the start, which is exhausting and puts people off the sport entirely.
Heavier skiers, read this before you buy. A lot of size charts stop at 69 in, which leaves anyone over about 100 kg being told to ski on a board that will not float them properly. A 71 in ski exists and it is the right call for most skiers over 100 kg. We stock the Radar Senate Graphite and the Radar Session in 71 in. If a chart or a shop tells you 69 is as big as it gets, that is the chart's limit, not yours.
Which ski should I actually buy?
These are the three we hand people most often, and what each one is for.
| Ski | Sizes we stock | Who it is for |
|---|---|---|
| Radar Session | 65, 67, 69, 71 in | Learning to slalom, and recreational skiing. Forgiving, easy to get up on, easy to turn. |
| Radar Senate Graphite | 65, 67, 69, 71 in | The step up. Once you are holding a line and want a ski that turns properly. The most popular ski we sell. |
| Radar TRA | 63, 65 in | Kids moving off combos onto a single ski. Also in a girls version. |
If you are learning, the Session in the right length beats a better ski in the wrong one every time. Buy the length first and the model second.
Should I buy combo skis or a slalom ski?
| Combo skis (a pair) | Slalom ski (single) | |
|---|---|---|
| Getting up | Much easier, two skis are stable | Harder, needs technique or a deep water start |
| Best for | First timers, kids, shared family use | Anyone who can already drop a ski |
| Turning | Limited | The whole point of the sport |
| Speed | Comfortable slower | Wants proper boat speed |
| Cost | Lower | Higher |
Buy combos if nobody in the household can ski yet. Most combo pairs have one ski with a rear toe plate, so a skier can drop the second ski and start slaloming on the same set once they are ready. That is the natural progression path and it saves buying twice.
Buy a dedicated slalom ski once you can comfortably drop a ski and hold a course. A real slalom ski turns in a way no combo ski can, and that is where the sport gets good.
What size combo skis do I need?
Combos are far less fussy than slalom skis, because you are on two of them.
| Rider weight | Combo ski length |
|---|---|
| Under 25 kg | 46 in or a kids trainer set |
| 25 to 45 kg | 54 to 58 in |
| 45 to 70 kg | 63 to 65 in |
| 70 to 90 kg | 65 to 67 in |
| Over 90 kg | 67 in and up |
For young kids, a trainer set with a tow bar or a connector between the tips is worth far more than getting the length exactly right. It keeps the skis pointed forward, which is the only thing stopping a five year old doing the splits.
How do slalom ski bindings fit?
Snug, with your heel locked and no movement side to side. A slalom binding is closer to a boot than a slipper, and a loose one costs you every bit of edge control.
| Binding type | Fits | Notes |
|---|---|---|
| Rubber adjustable | A range of shoe sizes | The default. Easy on and off, shared use, good value. |
| High wrap rubber | A range, narrower | More ankle support and response than a standard rubber binding |
| Hardshell | One rider | Maximum response. Requires a release system and proper setup. |
| Rear toe plate | Any | The rear foot loop on a combo or entry slalom ski |
Beginners and shared skis: rubber adjustable. Serious course skiers: hardshell, fitted properly, with the release settings checked.
On hardshells, the release matters. A ski that does not release in a bad fall is how knees and ankles get hurt. Do not run a hardshell setup you have not had set up correctly.
What boat speed should I ski at?
| Skier | Typical speed |
|---|---|
| Small child on combos | 20 to 26 km/h |
| Adult learning on combos | 30 to 40 km/h |
| Recreational slalom | 46 to 53 km/h |
| Course slalom, men | Up to 58 km/h (36 mph) |
| Course slalom, women | Up to 55 km/h (34 mph) |
Skiing faster than you are comfortable with does not help you learn. It just makes the falls worse. Start slower than you think, then build up.
What else do I need?
- A lifejacket. In NSW anyone being towed must wear a Level 50S or above lifejacket at all times, and inflatable jackets are not recommended for towing. Read the NSW rules
- A ski rope and handle. Ski ropes are a different build to wakeboard ropes and the standard length is different. Rope and handle guide
- A ski sleeve or bag. Fins and bevels are the fragile part of a slalom ski, and most damage happens in transit, not on the water.
Quick answers
Does height matter for ski size? No. Weight and boat speed only.
Can I use one ski for the whole family? Not well. Slalom skis are weight specific and the binding has to fit. Combos share far better.
Do I need a wide ski? Wide body skis have more surface area, so they get a heavier or slower skier up more easily and plane at lower speed. They are a good option for a heavier recreational skier who does not want to ski at 50 km/h.
Are older skis still fine? A ski from the last ten years is fine. Much older skis are usually narrower and less forgiving than anything modern, and the binding rubber will have perished.
How do I know if my ski is too short? You will struggle to get up, it will feel like it is sinking under you at speed, and you will be working hard just to stay on top of the water.
Not sure what to get?
Tell us your weight and what speed you ski at and we will size a ski for you properly. Call (02) 4577 5333 or come into the shop at Shop 2, 317 Windsor Road, Vineyard NSW.
More than 100,000 Australian customers, 4.8 stars from 280 plus Google reviews, and free express shipping over $99.
Last reviewed August 2026. Size charts vary by brand, so always check the chart on the product page before you buy.