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What is Book Time?

The Tripyramids

There’s an expression used in many hiking guides called book time. Also known as Naismith’s rule, it refers to the minimum time that it would take an inexperienced hiker to complete a trail segment. It’s based on the following metric: 30 minutes for each mile of distance or 1,000 feet of elevation gain.

While it is a useful benchmark for rough time estimation and route planning, it’s often taken too literally by people. The truth is that hiking speed is dependent on many other factors including the difficulty of a trail, the number of people in your group, pack weight, season, weather conditions, and physical fitness.

There are times when I hike slower than book time, due to the difficulty of the trail or the weather. For example, in winter, I usually plan on 1 mile per hour when hiking in the White Mountains, as I’ve found this is a reliable pace for two fit hikers over a day, regardless of elevation gain.

However, for three-season hiking time estimates, book time tends to be remarkably accurate for predicting how long a hike will take and whether there will be enough daylight to finish a hike without a headlamp.

Updated 2023.

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  1. Good post. Book time is just a guide. It was originally intended as the minimum time taken to complete a route and doesn't include stops of any sort.

    Those times are used in many places not just the White Mountains. They were first put forward by Scottish mountaineer W.W.Naismith in 1892 and are known in Britain as Naismith's Rule. There's a good piece about it on Wikipedia:'s_Rule

  2. Quick question about the 30 min mile/1k ft metric.

    Does that mean that 2 miles w/ 1k ft gain would "book time" take 1.5 hrs? (1hr distance + .5hrs elevation) Thanks!

  3. Good post. Chapman, an Australian walking guide author has recommended times. They are always much faster than what we take.

    Only reason I look at them is to work out if we might be in camp before dark i.e. we usually double them…

  4. Interesting calculation. The hike I take most often as an overnighter in Big Bend starts as a 1500′ climb in 3.5 miles up to the top of Pinnacles Pass. I used to average 1 MPH on it and was tripping over my tongue by the time I got to the top. After I lost 20 lb. a few years ago, I consistently make it in 2-1/2 hours and have plenty of gas in the tank when I get there. I’m not setting speed records but am hitting a good average. 3.5 miles x 30 minutes/mile + 1500′ x 30 minutes/1000 feet=2.5 hours. I’m usually accompanied by a young grandson on that hike.

    Most hiking times I’ve seen are about half the time it really takes me. Of course, I’m constantly stopping for the view, taking pictures, checking out rocks, explaining things to the grandson, etc.

  5. Age is my main factor these days. I call it the Cuthbert rule. It is in pretty much in line with the inexperienced hiker. A few years ago I met an 86 year old man on the summit of Mt. Jefferson. He had us all mesmerized by his stories and knowledge. He couldn’t stand up straight and when he hobbled off with his walking stick (and with grandson by his side) I wondered how he even made it up, never mind how long it took.

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