How to plan the time needed for a long distance hike

This had been my first really long hike the route of which I had completely planned myself. All the other long hikes I had done in the US and Australia had been existing long distance trails with map sets and/or guidebooks. And of course other people had hiked those trails before and had given me a pretty good estimation on how long the hike would take.

My hike through Western Europe has been very different. Although I was using existing long distance trails as well I had been piecing them together creating my very own route that nobody had hiked before in that combination. I therefore could only guestimate how long it would take me. To get a rough idea I had downloaded gpx tracks for the whole route and connected them. Now I could measure the distance on my computer and the result was around 4,850 km. I knew from experience that I can usually average 30 km per day. I double checked that by comparing this to my daily mileage on the PCT. Assuming the same amount of full and half rest days I came to a finish date for my European hike and booked my flights accordingly.

Now, at the end of my hike I have learnt a lot... I had to realise that I have very much miscalculated the time needed for this hike. I have only been able to make IT to the end in time by taking all sorts of planned and unplanned shortcuts and by even skipping a section of trail that I had already hiked several years ago.

Why have I been so much off my planning? In hindsight I can say that there have been several factors.

Inaccurate length of route: I have already described that I had downloaded gpx tracks for the whole distance and measured the length of the route based on it. But with anything you download from the internet you never know what quality you get. The tracks for Germany and the Spanish Caminos turned out to be very accurate. But the tracks for France which made up a good third of my hike were only very basic. They consisted of very few track points only. When on the ground the trail was meandering around or taking long switchbacks my gpx track would only show a straight line. And of course this straight line was much shorter than the real trail. I have no way of double checking it but I guess that the real distance I have hiked in France is about 10-15% longer than planned.
Lesson learnt: Make sure you have the accurate length of your route. If in doubt add a buffer for planning inaccuracies.

Rest days: I knew from long experience that I need a rest day about once a week or at least every 10 days. I had calculated 2 full rest days per month and was expecting that I could add a couple of Nero days per month by exceeding my daily average. But the amount of rest days needed was based on my hiking experience in the US and Australia where your usual trail town is pretty boring. You can concentrate on what a hiker has to do on a rest day: rest and eat! There is not much else in those towns to distract you. The trail towns on my European hike were very different. They were major tourist destinations themselves. You could spend several days sightseeing in places like Basel, Grenoble, Carcassonne, Bilbao. And therefore I was facing a dilemma in each trail town. I really needed the rest, but I also wanted to see the sights! Unfortunately, sightseeing is not resting and I usually left town about as tired as I had entered it. I would have needed the double amount of rest days: one day for resting and town chores and one day for sightseeing.
Lesson learnt: If the trail towns have lots of sights and you are interested in seeing them you need a separate sightseeing day. You will not get rest on a sightseeing day!

Abundance of resupply options: I usually came across a shop every day, sometimes several times per day. I rarely had to carry food for more than a couple of days. Great! That means less weight to carry. But it also meant more time spent shopping! Every day I had to find the supermarket, do my shopping and find a nice place to eat it. Because of course with all this abundance of food I ate a lot of fresh fruit and other heavy stuff that I did not want to carry too far away from the shop. I don't mean to complain about this. It was great to get all this great food daily and I enjoyed the local specialties tremendously but I had not considered how time consuming it is. Time that cannot be used for hiking any more.
Lesson learnt: Plenty of resupply options means less pack weight but also more time spent shopping.

Wrong daily mileage: My assumption of daily mileage had been based on my thruhike of the PCT. It should have dawned on me that I had needed almost the same amount of time for the AT which is much shorter, but had a more difficult terrain. I had stupidly assumed that hiking in civilised Europe would be easy. No wilderness, no bushwhacking. I was wrong. The Pyrenees turned out to be some of the most difficult hiking I have ever done and my daily mileage was halved. And although the French mountain ranges of the Vosges and Jura are not quite alpine I still had to deal with a daily elevation gain of 1,000 m plus. The PCT is all well engineered trail accessible for horses whereas the French do not seem to believe much in switchbacks and other commodities... The difficulty of the terrain and thus my daily mileage was alternating greatly from dead easy Spanish pilgrimage trails to suicidally steep ascents in the Pyrenees. But overall a daily average of 30 km was a bit too high.
Lesson learnt: From now on I will only assume a daily mileage of 30 km/20 miles if I am dead sure that I will encounter relatively easy trail and moderate elevation gains.

Climate: Of course I had studied climate charts and knew what sort of weather to expect. But I had only considered temperature and precipitation. The big problem turned out to be humidity in combination with heat in Southern France and Northern Spain. It was draining all energy from me and chafing became a real problem. Yes, you can still maintain a high mileage in that climate but it is no fun...
Lesson learnt: Don't forget humidity in your climate considerations.

Fixed finish date: Because I had to book a flight to get to my next adventure in the US I had a fixed end date. And because I don't have an apartment any more I did not want to linger too long in Berlin where my storage unit is. I therefore calculated only 4 days between my planned finish date in Spain and my flight to the US. I somehow assumed it would most likely take me less time to finish. Big mistake: the finish date turned into a Damocles' sword and I constantly felt in a hurry. Instead of staying and resting where I liked a place I felt a constant time pressure.
Lesson learnt: If at all possible don't have a fix end date for such a long and unpredictable hike. But if you have to have one like me, plan enough buffer time. If you then finish with some buffer time left, have a plan for what to do with the rest of the time like another short hike, sightseeing or visiting friends. Don't plan to hike till the very last day!

Alternate shortcuts: This is at least one point I had taken into account. I had prepared a couple of alternate short cuts and when I realised that I was running out of time I took them instead of sticking to my original plan. But not all shortcuts were real alternatives. I had a lot of shortcuts for the beginning of my trip but they were useless because I had not yet realised at that time that I needed them. I had only one possible shortcut for the end of my trip: taking the popular Camino Frances instead of the less travelled Camino del Norte and Primitivo. But faced with that option I realised that it was such a bad alternative that it would spoil the enjoyment of the trip. I could not bring myself to hike with thousands of other pilgrims in the blazing sun in the height of summer tourist season.
Lesson learnt: Try to have attractive alternate routes (shorter and longer) for the last stages of your trip when your finish date is already predictable.

Bottom line: So far I have always roughly calculated to hike 850 - 900 km per month. In easy terrain I was even able to do up to 1,000 km. But for any further European hikes I will definitely reduce that to 750 km per month in order to have an enjoyable hike.