Naismith's Rule Hiking Time Calculator

Naismith's Rule (1892) is the classic mountaineering estimate for how long a hike will take: allow 1 hour for every 5 km of distance, plus 1 additional hour for every 600 m of elevation gain, since climbing costs far more time per unit of distance than walking flat ground — verified via web search against Wikipedia's own Naismith's Rule reference and outdoor-recreation guides rather than relied on from memory. This calculator keeps that 600 m/hour ascent rate fixed, since it's the constant that defines the rule, but lets the flat-ground pace be adjusted from the traditional 5 km/h assumption — not every hiker walks at exactly that speed.

The two components are also reported separately (flat-ground time and added ascent time) so you can see how much of the estimate comes from distance versus climbing, rather than just a single combined number.

This is a rule of thumb, not a precise prediction — it doesn't account for trail surface, pack weight, rest breaks, or descent (some fuller variants add a Langmuir correction that adjusts for steep or shallow descents, which this calculator deliberately leaves out to keep the input simple and avoid guessing at a descent gradient it doesn't have enough information to compute accurately).