The Simple Formula to Calculate Hiking Speed
Planning a backpacking trip involves a lot of preparation and planning. The first detail to figure out is how long you'll be out on the trails. Your timeline is usually driven by your hiking speed. If you only have a couple of days to backpack then you won't be able to take on any 75 mile loops. You also don't want to underestimate and plan a 20 mile loop for a 7 day trip.
But what about those ones that are in between? Is 30 miles the right length for a 3 day trip? Can 30 miles be done in 2 days? What about 25 miles? Luckily there's a simple rule of thumb you can use called Naismith's rule which is:
Naismith's Rule for Calculating Hiking Speed
- Allow 1 hour for every 3 miles of flat, smooth terrain.
- Add 1 hour for every 2,000 feet of elevation gain.
Naismith's rule was created way back in 1892 by Scottish mountaineer William Naismith.
This rule is a simple approximation for a hiker in good, athletic shape who is carrying a moderately heavy backpack. If you're out of shape or if you have a heavy pack (45+ pounds) then your speed on flat terrain will be closer to 2 mph than the 3 mph Naismith estimated.
There are a lot of calculators online and other ways to estimate your speed but this simple rule is a close approximation and is much faster and easier to use than the more complex calculations.
Example of Calculating Your Average Hiking Speed
Here's a couple examples showing how to calculate your hiking time:
- On a completely flat trail that's 21 miles long, it will take 7 hours to complete.
- On a hike up a large hill that's 15 miles long and has an elevation gain of 2,000 feet, it will take 6 hours to complete. (5 hours for the 15 miles then 1 hour for the 2,000 foot of elevation gain).
- On a hike up a steep mountain that's 6 miles long and has 6,000 feet of elevation gain you can estimate 5 hours to complete. (2 hours for the 6 miles then 3 hours for 6,000 feet of elevation gain)
Adjustments to Naismith's Rule
If you want to get really specific you can throw in some additional tweaks to this formula.
For every 1,000 feet of elevation loss, you can subtract 10 minutes. This is pretty intuitive since you can move more quickly going down a mountain instead vs going up.
If you extrapolate that out to 2,000 feet though you can see that you'll subtract 20 minutes total coming down. Naismith's rule says to add 1 hour to go up 2,000 feet so if you are on a trail with a lot of up and down you'll net out at an additional 40 minutes to go up 2,000 feet then back down 2,000 feet.
How to More Accurately Estimate Your Hiking Speed
The best way to more accurately figure out your hiking speed is simple; just measure it.
Throw on a backpack with 30-40 pounds in it and go for a 1 mile hike near your house and use that as your baseline. You can use that rate to tweak Naismith's formula.
Also keep in mind that when you're backpacking you'll be stopping to eat, filter water, answer nature's call, and adjust your pack. All of these small stoppages add up and need to be accounted for in your estimates.
Other Factors that Affect Hiking Speed
In addition to the adjustments mentioned above, there are a couple of factors you can estimate to get a feel for whether you need to tweak your time estimate up or down just based on your gear, terrain and conditioning.
- Backpack weight affecting hiking speed
- If you're going on a day hike and you're only carrying the essentials, you'll be able to move much faster than if you're carrying a fully loaded 45 pound pack with enough gear for a 7 day excursion. When estimating your hiking speed, weigh your pack and if it weighs more than 35-40 pounds you'll probably want to lower your average speed down from 3 mph to 2.5 mph or so.
- Terrain affect on hiking speed
- Terrain has an obvious affect on hiking speed and it's shown in Naismith's formula. Going up hill will add significant time to your hike and you'll be averaging closer to 1 mph on an incline instead of the 3 mph you would get on flat terrain. Additionally, rocky terrain or areas that have stream crossings and downed trees can add time to your hike. These will be hard to pinpoint before your trip but you should have a general idea of how smooth the trails will be. If you're going somewhere popular the trails will probably be smooth. If you're going off the beaten path then you might want to be conservative and estimate 2 mph instead of 3 mph on flat terrain.
- Strength and conditioning affect on hiking speed
- This one is obvious but can sometimes be hard to estimate without actually hiking and getting real world experience. Someone in really good shape who can run a 6 minute mile will probably be able to sustain something closer to 3-3.5mph while hiking on flat terrain. Another person who rarely exercises and isn't used to carrying a lot of weight will probably be closer to 2 mph just due to their muscles and cardiovascular health.
- Trekking poles to help with hiking speed
- Trekking poles can be really useful for people who have knee problems, but they can also help increase your speed when going up an incline and slightly help your speed on flat terrain. Trekking poles help you move more quickly over obstacles like rocky terrain and small stream crossings. These little slow downs add up over the course of several days and you could estimate trekking poles to add 5-10% to your estimated speed.
How to Find Trail Length and Elevation Gain
If you're not sure where to find the trail information you need to estimate your hiking time, there are 2 resources I'd recommend:
For trail length, use Alltrails.com. This site has almost every trail in the world mapped out with reviews and details like length and difficulty. Use this site to get the trail length.
For elevation change I like to use Caltopo.com. This site not only shows elevation change, but provides a convenient chart showing inclines and declines so you can account for the slow downs when you're climbing up and the small speed increase you'll pick up when you are headed back down.
An average hiking speed of 3 mph is a good starting point. If you're not in great shape, have a really heavy pack, or will be hiking at a higher elevation, you should use 2 mph as an estimate.
Of course no estimate is a replacement for real world experience so the sooner you can get out there and measure your actual hiking speed, the better. Once you get a feel for your normal speed you'll be able to easily estimate your average hiking speed on future trips with different terrain and gear pack outs.