How to Estimate How Long It Takes to Complete a Hike

Climbing up Acra Point
Average read time 4 min

You’re planning that hike or yearly backpacking trip, and you’re wondering how long it will take to cover that many miles? That’s a good question! Estimating your time to complete a hike or a trail section is critical to trip planning and success. Many people overestimate their ability to complete a hike, overshoot their time finishing in the dark, or can’t make the mileage on that rugged 5-day trip. Some plans go wrong, and hikers end up being rescued by rangers. Not a way to spend your outing!

Why is it important to gauge your time?

Walking speed and time are critical to planning and reaching hiking and backpacking goals. Reaching destinations in timeframes planned, making realistic plans, preventing overexertion, lowering the risk of injury, and increasing the enjoyment of your trip are a few reasons this skill is essential.

How do you estimate the time to reach your destination?

William Wilson Naismith was a Scottish Mountaineer, Physical Educator, and founder of the Scottish Mountaineering Club.

Naismith’s noteworthy contribution to hiking is his formula, Naismith’s Rule, for estimating how long it would take to walk or hike a route on level ground and up and downhill. Naismith’s Rule was vital as it enabled people to plan how long it would complete an intended trip.

Naismith’s Rule was quite simple. The rule stated that people should allow one hour for three-level miles on a map and add one hour for every 2000 feet climbed. Naismith’s rule also had a downhill estimate of minus 10 minutes for every 984 feet descent for slopes between 5 and 12 degrees or 10 minutes per 984 feet descent for slopes greater than 12 degrees. It is puzzling that Naismith does not adjust for more extreme descent grades as the hiker will need to slow down.

Naismith’s Rule makes no adjustments for the difficulty underfoot, the weather, or a load carried. His rule may apply to hikers with reasonable fitness on a path free of obstacles in good conditions with no weight on your back. The time to the destination also is lengthed by breaks, sightseeing, chatter between hikers (yes, that slows you down), and navigational issues.

Another skill post: How to Hang a Bear Bag and Secure Food

Trail conditions can slow you down
Scott | copyright Challenged Hiking Trail conditions can slow you down

Wilderness Tech Tips recommends taking the Naismith value and add 50 % to adjust for the items mentioned above, or some have suggested new hikers add 20%. Ultimately the results will need to be changed due to your hiking ability.

Tranter’s corrections

There is a correction for Naismith’s Rule that takes into consideration fitness. Fitness is determined by the time it takes to climb 1000 feet over a distance of ½ mile (800 m).

Note: Climbing a 1000' in a half a mile as fast as you can, is quite rigorous. I could not find any guidance on how this time is detirmed. I'll assume it is the time taken for a person's regular hiking speed, not a stress test.

Using the table below, you calculate Naismith’s Rule and then use the information to correct it.

Tranter's corrections
Wiki Commons Tranter’s corrections

For example, if Naismith’s rule estimates a travel time of 5 hours and your fitness level is 50, you should allow 8.5 hours. Adjustments can also be made for the terrain. Recall, Naismith’s Rule was based on excellent trail conditions. If the trail your hiking is rough, has scrambling, or you’re carrying a heavy pack, drop a level to adjust your time.

The reality is:

Only trial and error will provide you the ability to estimate how long it will take to hike to a destination. You can attempt Naismith’s Rule with the correction if you would like but always rely on your experience. Your past hiking trips will give you a good idea of how long it will take for you to hike to a destination. 

Start small. Doing day hikes of different lengths and difficulties will help you figure out your timing for longer trips. Then try an overnight with a heavier pack. Don’t just jump into a 5-day backpacking trip and think that Naismith’s Rule will give you your time estimates. It probably won’t. It is worth noting that once you have figured out your hiking speeds, go ahead and plug these into Naismith’s equation!

As you become more trail hardened, improve your fitness, get better at navigating, more skilled at lightweight packing, and many other little things that will increase your hiking efficiency, your hiking times will change. Once you have figured out your hiking abilities, you can then start planning with precision. 

Time changes you

Back in the 1980s, I could hike much faster than today. I still navigate well, have gone ultralight, but the fact is that my age limits my aerobic capacity. I also don’t bounce back from injuries as I once did, so I intentionally hike slower as a preventative measure. I have to say; I enjoy the forest more now than ever. 

Be flexible

My recommendation is to build flexibility into your trips. Don’t be too strict with time and destination on long-duration trips. The longer your planned trip, the more likely you will need to deviate from your plan.

Use tech (high and low)

You can use hiking apps/maps such as Gaia GPS to help track time and trail stats. Trail guides may help as some give estimated times on a trail for an average hiker to complete. If you don’t have average fitness, it will take you longer; if you’re a superhero, it won’t. Using topographic maps is a critical skill for the backcountry traveler. Yes, low-tech, but still essential. You can pair it with an app like Avanza Maps.

The group effect

Time to destination does become tricky when you hike with a group. Remember, the group hikes as fast as the slowest member. The reality is everyone should have an idea of their hiking ability.