How long will your hike really take? An honest way to plan hiking time

The gap between the time a route "should" take and the time it actually takes is where most bad days on a mountain begin. Not in a storm or a wrong turn, but in an estimate that was quietly optimistic from the start.

The real answer to "how long will my hike take" is not a number you look up. It is a short method: get a base estimate, correct it for the things that make a real day slower, then work backwards from the light to a turnaround. Do that and you head down with time in hand. Skip it and you are still descending when the light goes, wondering where the hours went. This is the planning hub for everything on Datum Heights, the whole method in one place, with the deeper pieces linked at each step.

Key takeaways

• A trustworthy hike time is a method, not a lookup: base estimate, then corrections, then turnaround.
• Standard estimates (Naismith, alpine-club norms) describe a fit walker not stopping, so they read low for a real day.
• The corrections that matter: descent, breaks, pack, fatigue, terrain, altitude, and group size.
• Always finish by setting a turnaround time from the daylight, not just a total.

Step 1: get a base estimate

Start with a formula that turns a line on the map into a number. Two well-worn ones do the job.

Naismith's Rule: allow one hour per 5 km, plus one hour per 600 m of ascent. Fast, and good enough as a floor. The full rule, its shortcut, and its blind spots are in our Naismith explainer.

The alpine-club norm: the German and Swiss Alpine Clubs plan by height gained, roughly 300 to 400 m of ascent, 500 to 800 m of descent, and 4 km of horizontal distance per hour, combined by adding the horizontal time, the larger vertical time, and half the smaller vertical time. The German version is codified in the standard DIN 33466:2004-05, which sets the walking times printed on German-language trail signs.

Both describe the same walker: fit, steady, unloaded, not stopping, in good conditions. That is why the base estimate is a starting point, not the answer. What you do next makes it real.

Step 2: correct for your real day

Every base estimate assumes an ideal. Your day differs on at least a few counts, and each difference adds time.

Descent isn't free. Classic Naismith counts only distance and ascent. A steep, knee-jarring descent is slower than the flat, and it usually lands at the end of the day. Langmuir's correction fixes this: subtract a little for gentle downhills, add time for steep ones (Langmuir, E., Mountaincraft and Leadership, 4th ed., 2013).

Breaks add up. Lunch, layers, photos, water, navigation. Real stops routinely add 30 minutes to an hour over a day, and no formula includes them.

Your pace isn't the textbook pace. The flat 3 mph figure is a ceiling; real terrain, a pack, and fatigue pull it down, often to 2 to 4 km/h. Find the band you actually move at in our hiking-pace guide.

The ground fights back. Rough, rocky, boggy, or pathless terrain runs at roughly 60% of trail speed, and snow or scree can halve it.

Altitude thins everything. Above about 2,000 to 2,500 m the same climb costs more time, and more the higher you go.

A group moves at its slowest member. Pace the plan to the slowest person, not the fastest, and remember that larger groups lose more time at every stop.

A practical shortcut until you have your own data: treat the base estimate as the minimum and plan for a third to a half more.

Step 3: set a turnaround from the daylight

This is the step that turns a time estimate into a safety plan, and it is the one people skip. Once you have a realistic total, don't just check it fits the day. Work backwards from sunset, with a margin, to the latest moment you can still be heading up. Reach that time and you turn around, wherever you are.

A turnaround is a decision you make in the calm of the kitchen table, so you don't have to make it badly on a cold ridge with the light going. Size yours with the turnaround & daylight tool.

A worked example

Take a route of 14 km with 900 m of ascent and 900 m of descent.

• Base (Naismith): 14 km at 5 km/h is 2 h 48 m; 900 m of ascent at 600 m/h is another 1 h 30 m. About 4 h 20 m moving.
• Corrections: add roughly 30 m for the steep final descent, 45 m of breaks, and a third for a moderate pack and a long day.
• Realistic plan: closer to 6 h 30 to 7 h car to car.
• Turnaround: if the light goes at 20:00 and the descent alone is about 2 h 15, you want to be at the top by 17:00 at the latest. A summit not reached by then means turning around.

That is the difference between "it's a four-hour hike" and a plan you can actually trust.

Let the tools do the arithmetic

The method is worth understanding, but you don't have to run it by hand every time. Datum Heights builds the corrections in:

• the "Can I do this hike?" planner, a route plus your inputs, returning an honest go or no-go with time and turnaround.
• the Hike Time calculator, Naismith plus the corrections, showing its working.
• the Turnaround & Daylight tool, the latest safe start and turnaround for the daylight you have.

Frequently asked questions

How do you calculate how long a hike will take?

Start with a base estimate, Naismith's Rule (1 hour per 5 km plus 1 hour per 600 m of ascent) or an alpine-club norm (about 300 to 400 m of ascent per hour), then add time for descent, breaks, pack, fatigue, rough terrain, and altitude. A common rule of thumb is to plan for a third to a half more than the base figure, then set a turnaround time from the daylight.

Why do hikes always take longer than expected?

Because the standard estimates describe a fit walker moving without stopping, and leave out what slows a real day: breaks, steep descents, a heavy pack, fatigue late in the day, rough ground, and altitude. Each adds time, and they stack, which is why an honest plan adds a margin on top of the formula.

How much time should I add to a hiking-time estimate?

There is no single figure, because it depends on your fitness, pack, the terrain, and how often you stop. A sensible starting point is to treat the base estimate as a minimum and plan for a third to a half more, then refine it once you have compared the formula against your own times on a few known routes.

What is a turnaround time?

It is the latest time you allow yourself to still be heading toward your goal. You set it before you start, by working backwards from sunset with a margin. When you reach it, you turn around regardless of how close you are. It is the simplest habit for not being caught out by darkness.

The short version

You can't look up how long a hike will take, you plan it. Get a base estimate from Naismith or an alpine-club norm, correct it for descent, breaks, pack, fatigue, terrain, and altitude, then set a turnaround from the daylight so the mountain never sets your schedule for you. Understand the method once, then let the tools run it for every route you plan.

Put a real route through it with the "Can I do this hike?" planner.