Hiking Time Calculator Formula

Understand the math behind the hiking time calculator. Each variable explained with a worked example.

Use the Hiking Time Calculator

Formulas Used

Moving Time

moving_time = round((flat_time_hr + climb_time_hr) * fitness_factor * 10) / 10

Total Time (with breaks)

total_time = round((flat_time_hr + climb_time_hr) * fitness_factor * 1.2 * 10) / 10

Average Moving Speed

avg_speed = round(distance_miles / ((flat_time_hr + climb_time_hr) * fitness_factor) * 10) / 10

Variables

VariableDescriptionDefault
distance_milesTrail Distance(miles)8
elevation_gain_ftTotal Elevation Gain(ft)2000
fitness_factorFitness Level1
flat_time_hrDerived value= distance_miles / 3calculated
climb_time_hrDerived value= elevation_gain_ft / 2000calculated

How It Works

How Hiking Time Is Estimated

Naismith's Rule

Developed in 1892 by Scottish mountaineer William Naismith:

Time = Distance / Speed + Elevation Gain / Climbing Rate

  • Flat walking speed: ~3 miles per hour
  • Climbing rate: ~2,000 ft per hour (adds time for elevation gain)

    • Adjustments

  • Fitness factor: Adjusts for individual speed
  • Break time: Add 20% for rest stops, water breaks, photos, and navigation
  • Descent: Steep descents are almost as slow as climbing. This calculator focuses on ascent.

    • Worked Example

    Estimate time for an 8-mile trail with 2,000 ft elevation gain, average fitness.

    distance_miles = 8elevation_gain_ft = 2000fitness_factor = 1
    1. 01Flat time = 8 / 3 = 2.67 hours.
    2. 02Climb time = 2000 / 2000 = 1.0 hours.
    3. 03Moving time = (2.67 + 1.0) x 1 = 3.67 hours.
    4. 04Total with breaks = 3.67 x 1.2 = 4.4 hours.
    5. 05Average speed = 8 / 3.67 = 2.2 mph.

    Frequently Asked Questions

    How accurate is Naismith's Rule?

    Naismith's Rule is a good baseline but tends to underestimate time for rough terrain, high altitude, or very steep trails. For technical terrain, add 30-50% more time. GPS watches with barometric altimeters give more accurate real-time data.

    What about descent time?

    Gentle downhill is faster than flat. Steep downhill (over 20%) is slower than flat because you must control your pace. As a rough guide, add half the climbing time for the descent of steep terrain.

    How should I plan my start time?

    Add a safety buffer of 1-2 hours to the estimated total time. Start early enough to finish well before sunset. In mountains, plan to be below treeline by early afternoon to avoid afternoon thunderstorms.

    Ready to run the numbers?

    Open Hiking Time Calculator