Know how long the route will take.
Naismith’s rule describes fit walkers on paths in reasonable conditions. Rough ground, snow, heat, heavy loads, navigation, group pace and fatigue all add time, and none of them is modelled. Time a known route to calibrate your own pace and climb allowance.
Model details & unit conventions ↗Naismith’s rule in metric: 5 km/h plus 10 minutes per 100 m of ascent, with Langmuir descent corrections and a worked 14 km hiking time example.
Lightning safety for hikers from NWS guidance: what counts as safe shelter, the 30-minute rule after thunder, flash-to-bang distance and storm timing.
Work out a hiking turnaround time from sunset, the return leg, breaks and a safety margin, with a worked example and the limits of Naismith’s rule.
Tobler’s hiking function gives walking speed on a slope: 6 × e^(−3.5 |S + 0.05|) km/h. See the speed table, the flat value and a map-based example.
Map scale explained: 1:25,000 means 1 mm is 25 m on the ground. Convert map distance, compare common scales and measure winding routes accurately.
Work out how much daylight is left: NOAA sunset assumes 0.833° of refraction, and twilight ends 6°, 12° or 18° below the horizon. Worked example.
Related toolsLoaded milesPack ledgerFood carry