Cross-country ski length: classic vs skate, weight vs height

Alpine skis are sized to your height. Cross-country skis are sized to your weight first, and the two methods can point at lengths 20 cm apart for the same person. This guide shows both, explains which one to trust, and works one skier through all of it.

Why weight comes first

A classic ski has a double camber: it arches upward under each foot. When you glide with your weight on both skis, the arch should hold the grip zone off the snow. When you kick on one ski, your weight flattens the arch and presses the grip zone into the snow so it can bite. A ski that is too stiff for you never grips. A ski that is too soft drags the grip zone along the snow while you glide.

Tahoe Trail Guide puts it directly: body weight is "the primary determining factor for the length of your skis." Wild Rock says the same for classic skis, which are "chosen primarily by the skier's weight, not height." Length and stiffness are built together by the manufacturer, so each model comes with its own weight range per length.

Tahoe Trail Guide adds a practical point. Recreational skis tolerate a wide band, with one example of a mid-range ski recommended for skiers between 140 and 175 lb, while a racing ski allows only about 10 to 20 lb. Count your winter clothing and anything you carry in your weight.

Ski length by weight

evo publishes a weight chart for adults, in centimetres. Ranges overlap because each brand's skis vary.

Source: evo cross-country ski size chart. Note the ceiling. Classic tops out at 210 and skate at 195, so a heavier skier does not get a longer ski, only a stiffer one.

Classic runs about 10 cm longer than skate at every weight.

Ski length by height

Height is the older method and still a useful cross-check. Three published versions disagree a little, and the disagreement is informative.

The Castanet piece on choosing equipment quotes Salomon as saying classic skis are generally 15 to 20 cm longer than your height. So the classic add-on runs from 10 to 25 cm depending on whom you ask. That spread is why height alone is a weak method for adults. For children evo gives a weight chart as well: a child between 55 and 65 lb takes a classic ski of 120 to 130 cm.

SkatePro's height chart for those Madshus skis runs like this.

SkatePro states that this chart covers only the Madshus Fjelltech M50 Skin and Panorama T50 Intelligrip backcountry skis on its page, and that length should match both weight and height.

One skier, three answers

Take a skier who is 5'4" (64 inches, 163 cm) and weighs 140 lb. Here is what each method gives for classic skis.

• evo height formula: 64 × 2.6 + 15 = 181.4, so about 181 cm.
• SkatePro rule: 163 + 20 to 25 = 183 to 188 cm.
• evo weight chart: the 140 to 150 lb row says 190 to 205 cm. At exactly 140 lb the sensible reading is the low end of that range, around 190 to 195.

The height methods land near 181 to 188. The weight chart starts at 190. For skate skis the same person gets 64 × 2.6 + 5 = 171 cm from the formula and 180 to 195 from the weight chart, with the low end again closest at 180.

Which to follow? The weight chart, and the manufacturer's own table for the specific ski if you can find it. A 140 lb skier on a 181 cm ski chosen by height may land on a ski built for someone 20 lb lighter, and the grip zone will drag. If the weight row and height row disagree, go with the weight and pick a length at the short end of the range, since a short end gives you easier handling.

Classic and skate are different animals

Classic skis are longer and carry a grip zone under the foot, covered with wax or a textured skin. Skate skis have no grip zone and a different camber: stiff enough to stay flexed under a light load, soft enough to flatten when you push, according to the Castanet article. You cannot take a classic ski length and subtract a fixed number to get your skate length, because the stiffness requirement is different. The charts above handle that by giving separate ranges.

Touring skis are the shortest of the three in evo's table. They sit near your own height, with evo's formula listing height ±2 to 6 inches depending on skill, use and the ski.

Shorter or longer within the range

evo's advice for choosing within a range is concrete. Size shorter, closer to your chin, if you are a beginner or intermediate, weigh less than average for your height, or like quick turns. Size longer, nearer the top of your head, if you ski fast and aggressively, weigh more than average for your height, or ski mostly off trail. evo notes that a shorter ski is easier to turn but less stable than a longer one.

Wild Rock adds a rule of thumb: as skis get faster, they tend to get longer.

Checking the camber with paper

Tahoe Trail Guide describes a two-person test you can do in a shop with the actual skis. You need a sheet of paper.

1. Stand on both skis in your normal ski stance. Your helper slides the paper under the grip zone. It should slide freely front to back. If it will not move, the skis are probably too short or too soft for you. If it slides well past the zone, they are probably too long or too stiff.
2. Stand on one ski with the paper beneath it. Your helper tries to pull the paper out. If it will not come out without tearing, the ski is probably right. If it slides out easily, you are probably too light for that ski.

The author calls the test "not 100% accurate," because real kicking compresses the ski dynamically. If the result is unclear, try the next size down as well.

Related tools

Cross-country ski size chartClassic, skate and touring length from weight Ski pole size chartPole length to go with your skis Ski pole length guideAlpine, classic and skate poles compared