What this calculator does
It estimates how long a hike will take by combining your walking distance with the extra effort of climbing and descending, using the classic rule-of-thumb method hikers and mountaineers have relied on for trip planning for over a century.
The formula
This is based on Naismith’s Rule: allow 1 hour for every 5 km of flat-ground distance, plus 1 extra hour for every 600 meters of ascent. A common refinement (the Langmuir correction) adds a smaller time penalty for descent — this calculator adds roughly half the ascent rate, 1 hour per 1200 meters of descent, to account for the extra care and impact steep descents require.
The total estimated time is: Time = (Distance ÷ Pace) + (Ascent ÷ 600) + (Descent ÷ 1200), all converted to hours and minutes.
This is a planning estimate only — actual time varies with trail surface, fitness, pack weight, weather, and rest breaks, so always build in a safety margin for real hikes.