Ski speed tracker

Everyone overestimates how fast they ski. Put a number on it: open Self Speed at the top of the run, put the phone in a chest pocket, and check your max at the bottom. Works offline, which matters on a mountain with no signal.

How fast do people actually ski?

Most people who guess "about 80" are doing 45. The perception of speed scales with how close the snow is to your face, not with the actual number.

Cold kills phone batteries

This is the practical problem on the mountain, and it is worse than most people expect. Lithium-ion capacity drops sharply below freezing — a phone showing 60% in a warm gondola can shut down within minutes of being exposed at −10 °C.

• Keep the phone in an inside pocket, against body warmth, not an outer shell

pocket.

• A phone that shuts down from cold is usually not damaged. Warm it up slowly

and it will restart.

• Continuous GPS plus a lit screen plus cold is the worst combination for

battery life. Expect two to three hours, not a full day.

Offline is the point

Ski areas frequently have no usable mobile data. Self Speed caches itself in your browser the first time you load it, so opening it later with no signal still works — the GPS receiver in your phone does not need a data connection to get a fix, only to download the page.

Load it once on the hotel wifi before you go up.

Accuracy in the mountains

Mountains are a harder GPS environment than open ground. A steep valley wall blocks part of the sky, which reduces the number of visible satellites and degrades the fix. In a narrow couloir or dense trees, expect the accuracy figure to climb and the speed reading to get noisy.

Wide open pistes above the treeline give excellent readings. Tree-lined runs at the bottom of the mountain give the worst.

Vertical descent

GPS altitude is substantially less accurate than horizontal position — typically two to three times worse. For a rough sense of vertical metres it is fine; for anything you would compare between days, use a watch with a barometric altimeter, which measures air pressure directly.

Safety

Read it at the bottom, not on the way down. Skiing while looking at a screen is how people hit other people. Max speed is recorded automatically — you do not need to watch it happen.

Why skiing feels faster than it is

Perceived speed is driven by how close the ground is and how much is moving in your peripheral vision, not by actual velocity. Skiing puts your eyes about a metre above a surface rushing past, with trees and poles flicking by at the edge of vision.

A car at 90 km/h feels calm; you are sitting in a padded box, well insulated from the road. On skis, 45 km/h feels alarming. This is why almost everyone overestimates — the sensation is real, the number is not what they assume.

What actually limits your speed

Snow conditions matter more than technique. Firm, cold, groomed piste in the morning is fast. Soft afternoon slush can halve your top speed for the same effort and pitch.

Gradient sets the ceiling. A gentle blue run simply will not produce 70 km/h no matter how well you ski.

Air resistance rises with the square of speed, so each additional km/h costs disproportionately more. It is why speed skiers adopt an extreme tuck and wear smooth suits and aerodynamic helmets.

Ski length and tune matter at the top end. Longer skis are more stable at speed, and a fresh edge and base grind makes a measurable difference.

Safety, seriously

Speed is the dominant factor in the severity of skiing collisions. The FIS rules of conduct place responsibility for avoiding a collision on the uphill skier, which means whoever is going faster carries the duty of care.

Skiing fast is only defensible where you have clear sightlines, a wide empty piste and the skill to stop. Chasing a number on a busy run is how people get hurt — and the person you hit did not consent to your experiment.

Read your maximum at the bottom of the run. It is recorded automatically.

Frequently asked

How fast do beginners ski?

15 to 25 km/h on a green run. It feels considerably faster than that.

What is the fastest recorded skiing speed?

Ivan Origone set the speed skiing record at 254.958 km/h at Vars in 2016, on a purpose-built course with a gradient close to 45 degrees. This is a specialist discipline with dedicated equipment and bears no relation to piste skiing.

Will it work with the phone in my pocket?

Yes, though accuracy drops with your body between the phone and the sky. An inside chest pocket is the best compromise between signal and keeping the battery warm.

Does it work without mobile signal?

Yes, once loaded. GPS needs no data connection. Open the page on wifi before you go up.