On several occasions in the past I’ve been stood in the car park at Pen y Pass when people have emerged from the Miners’ or Pyg Tracks, looked at their mobiles or smart watches, and declared that they’ve done some impossible number of miles up and down the mountain.
Sorry, but it your device is calculating that from your step count, it’s almost certainly well out, whether this is a wrist or ankle device, or just a mobile phone app.
If you’re wearing or carrying a device which counts your steps, whichever path you take will see you walking well over 20,000 steps by the time you get back down, and probably nearer 25,000 (people with shorter legs will take more steps, of course).
However, whilst there’s no denying the number of steps you’ve taken – and devices do this quite accurately – converting steps to the distance walked only works accurately when you are maintaining your usual stride – on the level – something you won’t be doing much of on the mountain. When you walk up a gradient, you will take shorter paces, and the steeper the gradient, the shorter each pace will be. Thus, on a steep section, or where the path is stepped, your device will greatly overestimate the distance walked from the short steps you’ve been taking.
Also, uphill is not the same as downhill. I’ve got a long steep lane near my house which sees me taking some 5,000 steps to get to the top. But coming down it only records 4,000. It’s a fact that you take shorter steps when going uphill.
On the lower half of the Miners’ Track or Watkin Path, where it’s reasonably level and you can walk fairly normally, the distance walked will convert from your step count fairly accurately. However, on the upper half of these paths the distance will be considerably out because of the steepness.
Thus, whilst a round of the Pyg and Miners’ Tracks will see your steps converted to some 10 miles or more, in reality the route is less than 8 miles in total. A steeper path will exaggerate this discrepancy, whilst a path with an overall easier gradient, such as the Llanberis Path, will do so to a lesser degree as you will be walking more normally for more of the time.
There really isn’t a way of using a step counter to give an accurate distance walked on the mountain. If you want to know your true distance, it’s best to use an app or device that uses GPS to track your actual location.