Find the latest safe turnaround time for any hike.
Turnaround Calculator
Safe Turnaround
Select hiking time and fill in the details to see your turnaround time.
Always tell someone your planned turnaround time before you leave. Stick to it; conditions can change. When in doubt, turn around early.
⚠
For reference only. This calculator provides an estimated turnaround time based on Naismith's Rule. Actual hiking speed varies significantly with terrain, weather, fitness, pack weight, and group size. Always add a safety buffer. Getting caught out after dark in the mountains is dangerous. Check sunset time and weather forecast before every hike.
Mountain search and rescue (SAR) statistics consistently show that a large proportion of incidents involve hikers caught out after dark. Night hiking dramatically increases the risk of falls, navigation errors, and hypothermia from unexpected exposure.
The turnaround discipline
Experienced mountaineers and SAR professionals emphasise the turnaround time as a non-negotiable commitment, not a suggestion. The trap is summit fever: the temptation to push on when you are close to the top, even when your plan says turn back.
Plan before you leave: Calculate turnaround time at home, not on the mountain
Tell someone: Share your planned turnaround and return times with a contact
Stick to it: When turnaround time arrives, turn around. No exceptions.
Early is always safe: Arriving back at the car 2 hours early has no downside
The summit will still be there next time. The mountains will not renegotiate your turnaround time.
How to Calculate Turnaround Time
The turnaround time formula works backwards from sunset. You know when the sun sets, how long your total hike takes, and how much buffer you want. Everything else follows from those three numbers.
The formula
Turnaround = Sunset − (Hike time ÷ 2) − Buffer
This assumes the second half of the hike takes the same time as the first half. In practice, the return is often slower due to fatigue, so the buffer accounts for this.
Choosing your buffer
30 min: Minimum buffer for short, well-marked routes in good conditions
60 min: Standard buffer for most day hikes (recommended default)
90 min: Remote routes, unmarked terrain, early season, or group hiking
The sunset times used in this calculator are approximate averages for each region and month. Check the exact sunset time for your location on the day of your hike.
The 50% Rule
The 50% rule is a practical safety principle: if you have not reached the halfway point of your route by your planned turnaround time, you must turn around, even if you are not at the midpoint.
Why this works
Hiking speed varies. If you are moving slower than planned, waiting until you reach the halfway point physically means you will be out after dark. The turnaround time is a time constraint, not a distance constraint.
Calculate turnaround time based on total expected hiking duration
When that time comes, turn around, regardless of where you are on the route
A slower-than-expected outward leg means your return will also be slower
No exceptions for "being so close to the top"
Building in the habit
Set an alarm on your watch or phone for your turnaround time before you start. When it goes off, you turn around. This removes the emotional decision-making from the equation and makes safety automatic.
"Getting to the top is optional. Getting back is mandatory." — Ed Viesturs, first American to summit all 14 eight-thousanders.
Frequently asked questions
What is a turnaround time in hiking?
A turnaround time is the latest point in your hike where you must reverse direction and head back to the trailhead to return safely before dark. It is calculated by subtracting half the total hiking time and a safety buffer from sunset. Setting a firm turnaround time before leaving and respecting it is the single most important hiking safety practice. Most mountain rescues happen because hikers continued past the point of safe return.
How do I calculate the latest safe turnaround time?
The formula is: turnaround time = sunset time − (total hiking time ÷ 2) − safety buffer. For a 6-hour hike with a 17:30 sunset and 60-minute buffer: 17:30 − 3:00 − 1:00 = 13:30. You should be back at the trailhead by approximately 16:30, giving one hour before sunset. This calculator uses regional sunset tables to apply the formula automatically for any month and region.
What safety buffer should I add to my turnaround time?
A minimum 30-minute buffer is suitable for experienced hikers on familiar trails in good conditions. A 60-minute buffer is appropriate for most recreational hiking; it accounts for unexpected delays, wrong turns, and fatigue. A 90-minute buffer is recommended for mountain routes, unfamiliar terrain, groups, or when weather may deteriorate. The buffer also ensures you have sufficient light for route finding and photo stops on the way back.
What is the 50% rule in hiking?
The 50% rule states: if you have not reached the halfway point of your planned route by your turnaround time, you turn around, regardless of how you feel or what you can see ahead. This rule prevents summit fever from overriding the rational decision to turn back. It is especially important on out-and-back routes where the return leg takes as long as the outward leg.
Should I always stick to my turnaround time?
Yes. The turnaround time should be treated as a commitment, not a suggestion. The most common mountain accident scenario involves a hiker who felt strong, continued past the turnaround, reached the summit, and then descended in darkness on unfamiliar terrain. Descending in darkness on rocky or steep ground significantly increases the risk of falls. Tell someone your turnaround time before you leave and honour it.
What happens if I do not have enough daylight for my planned hike?
If the calculator shows insufficient daylight, your options are: start earlier that day, choose a shorter route, or postpone to a day with longer daylight. In autumn and winter, many mountain routes require pre-dawn starts to complete safely. Never attempt a route that the calculator flags as unsafe on the grounds that you are fast or the weather is good. Conditions can change rapidly in the mountains.
How do I find sunset time for my hiking location?
This calculator uses regional sunset tables averaged across Northern Europe, Central Europe, Southern Europe, and North America. For precise local sunset times, check a weather app (most show sunrise/sunset for your location) or use a dedicated astronomy app. Sunset time varies significantly by latitude. In summer in Northern Europe, sunset can be after 22:00, while in winter it can be before 16:00.
Should I carry a headlamp even if I plan to return before dark?
Yes, always carry a headlamp. Unexpected delays (injury, navigation error, helping another hiker) can mean returning after dark despite good planning. A headlamp weighs 80–100g and takes up minimal pack space. Most mountain rescue incidents that occur after dark involve hikers who did not carry a light because they planned to be back before sunset. A headlamp is non-negotiable safety equipment on any route over 3 hours.