Hiking Time Calculator (Naismith's Rule)
Naismith's Rule is a classic mountaineering formula (dating to 1892) for estimating hiking time: allow 1 hour for every 3 miles of distance, plus 1 additional hour for every 2,000 feet of ascent. It's a rough guideline, not an exact prediction — terrain, fitness, pack weight, and breaks all affect actual time.
Naismith's Rule as the page applies it
Distance and climb are timed separately, then your breaks are added on:
base hours = miles / 3 + ascent ft / 2000
total = base hours × 60 + break minutesThe defaults work through as 6 / 3 = 2 hours of walking plus 1000 / 2000 = 0.5 hours for the climb, giving a 2.50 hour base. Add the 20 minute break and the estimate is 2h 50m. The 1,000 ft of ascent costs half an hour - the same as an extra mile and a half of flat trail.
Where the rule is optimistic
William Naismith published this in 1892 for a fit hillwalker on a decent path carrying little. Real trips depart from that in predictable ways:
| Condition | Adjustment |
|---|---|
| Full overnight pack | Add 20-25% |
| Rough, rocky or boggy ground | Add 25-50% |
| Snow, scree or scrambling | Double it |
| Group of four or more | Add 10-20% |
Descent is not modelled at all. Langmuir's correction subtracts 10 minutes for every 1,000 ft lost on a gentle slope, but adds 10 minutes per 1,000 ft on steep ground - so a steep return leg can cost you time rather than save it.
Frequently asked questions
What is Naismith's Rule?
Allow one hour per 3 miles, plus one hour per 2,000 feet of ascent. William Naismith of the Scottish Mountaineering Club set it out in 1892 and it is still the standard first estimate.
How long does it take to hike 10 miles with 2,000 ft of climb?
About 4h 20m of moving time by this rule - 3h 20m for the distance and an hour for the ascent - before breaks. With a heavy pack, plan on five and a half hours.
Is Naismith's Rule accurate?
It is close for a fit walker on a good path and steadily optimistic for everyone else. Time one known hike against it, then keep your own correction factor and apply it every time.