Naismith Rule Hiking Time Calculator
Estimate hiking time with the Naismith Rule: 1 hour per 5 km plus 1 hour per 600 m ascent.
Adjust for fitness and terrain.
The Naismith Rule was devised by Scottish mountaineer William W. Naismith in 1892 and remains the most widely used formula for estimating hiking time.
The rule: Allow 1 hour for every 5 km of horizontal distance, plus 1 additional hour for every 600 m of ascent.
Descent is generally not added in the classic rule (Naismith assumed descending took about the same time as flat terrain), though some versions add 10 minutes per 300 m of steep descent.
Fitness adjustments (Tranter’s corrections):
- Very fit: reduce by 20%
- Average: no change
- Unfit: add 50%
- Carrying a heavy pack: add 20-30%
Example: A trail is 12 km with 900 m of ascent.
- Flat time: 12/5 = 2.4 hours
- Ascent time: 900/600 = 1.5 hours
- Total: 3.9 hours ≈ 3 hours 54 minutes
Limitations: The Naismith Rule assumes good trail conditions and a moderately fit hiker moving steadily without long breaks. Add time for rest stops, photography, navigation, and bad weather. In rough off-trail terrain, a correction factor of 1.5–2× is often needed.
Practical tips: Most day hikers average 3–4 km/h on flat trails with 200–300 m/h of climbing rate. Alpine mountaineers typically use 300–400 m/h of ascent in the Naismith formula.