Naismith's Rule Calculator
Hiking time estimation from distance and elevation
Use this Naismith's Rule calculator (also a quick naismith calculator and hiking time calculator) for instant hiking time calculation from distance and elevation gain. Enter your route details and the calculator shows total hiking time including ascent, descent, and recommended breaks. Adjust pace for your fitness level: fast (fit hillwalker), normal (standard pace), or slow (heavy pack or casual hiker). Based on Naismith's proven formula: 5 km/h horizontal + 1 hour per 600m ascent. Works for day hikes, mountain routes, and multi-day treks.
Result
Breakdown
Base walking time2h
Ascent time50m
Break time15 min
This calculator is for reference only. Actual times and distances vary with terrain, conditions, and individual pace. Always check official sources before racing or planning a route.
Sources: Mountaineering Scotland, Naismith's Rule and Naismith's Rule (1892)
What Is Naismith's Rule?
Naismith's Rule is a formula for estimating hiking time, created by Scottish mountaineer William W. Naismith in 1892. The rule states: allow 1 hour for every 5 km (3 miles) of horizontal distance, plus 1 hour for every 600 m (2,000 ft) of ascent. For example, a 10 km hike with 600 m elevation gain takes approximately 3 hours at normal pace. The rule assumes a reasonably fit hillwalker on decent terrain in fair weather. It remains the most widely used hiking time estimation method after more than 130 years. Staying hydrated extends your hiking endurance, so use our water intake calculator to plan how much water to carry.
Naismith's Rule Formula
The Naismith formula is: Time (hours) = Distance (km) ÷ 5 + Elevation gain (m) ÷ 600. In imperial units: Time (hours) = Distance (miles) ÷ 3 + Elevation gain (ft) ÷ 2000. This gives the base hiking time at normal pace (roughly 5 km/h on flat ground). The calculator above applies Tranter's corrections for different fitness levels: Fast (0.75×) for fit hillwalkers, Normal (1.0×) as baseline, and Slow (1.25×) for casual hikers or heavy packs. This calculator also applies Langmuir's descent correction from Mountaincraft and Leadership (1984), plus or minus 10 minutes per 300 m of descent depending on how steep the ground is.
Descent: Naismith as the base, Langmuir as the correction
Gentle descent is faster than flat ground and steep descent is slower, so a single descent rate cannot be right in both directions. This calculator uses two layers with two sources: Naismith's Rule (1892) for distance and ascent, and Eric Langmuir, Mountaincraft and Leadership (1984) for the descent correction, at 10 minutes per 300 m, subtracted on gentle ground and added on steep.
Langmuir splits the ground at 12 degrees. Between 5 and 12 degrees gravity does useful work and you cover distance faster than you would on the flat, so the correction comes off. Above 12 degrees the descent turns into a sequence of controlled steps that punish knees and slow you down, so the same figure goes on. Below 5 degrees the ground is close enough to flat that the base rule already covers it.
Langmuir is also worth quoting on when to skip it. Over a full day, he notes, the correction is usually left out altogether, because the time gained on gentle ground tends to cancel the time lost on steep ground. It earns its place on a lopsided route: a long steep drop off a summit, or a gentle track that runs downhill for hours. Leave the elevation loss at 0 and the calculator applies nothing.
One thing this page does not claim to know: whether the correction should scale with your pace setting. The published figure is a flat time adjustment rather than a rate, so it is applied after the pace multiplier and a fast walker gets the same 10 minutes per 300 m as a slow one. No source we have says otherwise, and we would rather say that than quietly invent a scaling.
Read the answer as a minimum, not an average. Naismith's Rule describes a fit walker moving steadily on a good path in decent weather. It says nothing about navigation, weather, mixed groups, heavy packs, broken ground or the time you spend looking at a map. Every one of those adds time and none of them subtracts it, which is why an underestimate here is the kind that finishes in the dark. Use the Slow setting and add your own margin on anything harder than a path.
When Is Naismith's Rule Inaccurate?
Naismith's Rule underestimates time in several situations: steep technical terrain (scrambling, boulder fields), poor weather (strong wind, rain, snow), navigating off-trail or in poor visibility, hiking with children or large groups, carrying heavy packs (25+ kg), and extreme altitude above 3000 m. The original rule also ignores descent on its own, which is what Langmuir's correction on this page adds. For these situations, use the Slow pace setting and add extra buffer time. For high-altitude hikes above 2500 m, check our altitude sickness checker before planning your route. To estimate energy expenditure during your hike, try our hiking calorie calculator. The rule works best for well-maintained trails in good weather with a fit solo hiker or small group.
Naismith's Rule vs Book Time vs Tobler
Three main hiking time formulas exist. Naismith's Rule (1892) is the simplest: 5 km/h + 600 m/h climb rate. Book Time (used in the AMC White Mountain Guide) is more conservative: 30 min/mile plus 30 min per 1000 ft, about 50% slower than Naismith. Tobler's Hiking Function (1993) is the most sophisticated, using an exponential formula that accounts for slope angle including descent. For most day hikes on good trails, Naismith's Rule gives a reliable minimum estimate. For mountain hiking with significant descent, consider adding descent time. For beginner-friendly estimates, use Book Time. Check our sunrise/sunset calculator to ensure you have enough daylight for your route, and use our backpack weight checker to verify your pack is within recommended limits.
Frequently asked questions
How long does it take to hike 10 km?
At normal pace on moderate terrain with 500m elevation gain, a 10 km hike takes approximately 2 hours 50 minutes of moving time. Add 20–30 minutes for breaks, making a total of about 3 hours 15 minutes. On flat terrain with no elevation, 10 km takes about 2 hours. Use the calculator above with your specific route data for a more accurate estimate.
How do I calculate hiking time from distance and elevation?
Use Naismith's Rule: divide your distance in km by 5 (giving hours for flat walking), then add your elevation gain in metres divided by 600 (giving hours for climbing). Add the two together. Example: 15 km with 800m gain = 3h flat + 1h 20min climbing = 4h 20min moving time. This is the standard way to calculate hiking time used by mountain organisations worldwide.
Is Naismith's Rule accurate?
Naismith's Rule is accurate to within 10–20% for fit hikers on well-maintained trails in good weather. It tends to underestimate time for steep, technical terrain and overestimate for easy, flat paths. The rule has been validated by modern GPS tracking data and remains the standard method used by hiking organisations worldwide.
Does Naismith's Rule account for descent?
The original rule does not. It covers flat distance and ascent only, and Naismith assumed descent was roughly cancelled out by the stops made on the way up. This calculator applies Eric Langmuir's correction from Mountaincraft and Leadership (1984), the only widely published descent adjustment to Naismith, and it runs in two directions: subtract 10 minutes per 300 m on gentle ground of 5 to 12 degrees, where gravity helps, and add 10 minutes per 300 m on steep ground over 12 degrees, where careful foot placement costs time. That is why the calculator asks how steep the descent is before it applies anything.
How much time should I add for breaks?
A common guideline is 5–10 minutes of rest per hour of hiking. For a 5-hour hike, plan for 30–50 minutes of breaks. Groups take longer breaks than solo hikers. On hot days, add extra time for water and shade breaks. The calculator above includes break recommendations in its output.
What is Naismith's Rule?
Naismith's Rule is a formula for estimating hiking time created by Scottish mountaineer William W. Naismith in 1892. The rule states: allow 1 hour for every 5 kilometres of horizontal distance, plus 1 additional hour for every 600 metres of ascent. It is the most widely used hiking time formula and forms the basis for most trail time estimates on maps and guidebooks worldwide.
How accurate is Naismith's Rule?
Naismith's Rule is reasonably accurate for fit hikers on good trails at steady pace. It tends to underestimate time on technical terrain, in bad weather, for groups with mixed fitness levels, or for hikers carrying heavy packs. The original rule does not account for descent at all, which is what Langmuir's correction on this page adds. Use the Slow pace multiplier (1.25×) as a safety buffer for mountain routes and first-time hikes.
How do I calculate hiking time for a 10km route with 500m elevation gain?
Using Naismith's Rule: distance time = 10 ÷ 5 = 2 hours. Climb time = 500 ÷ 600 = 0.83 hours (50 minutes). Total moving time = 2 hours 50 minutes at Normal pace. Add one 15-minute break for a total of approximately 3 hours 5 minutes. At Slow pace (×1.25) the moving time is 3 hours 33 minutes. Plan for 3.5–4 hours total including breaks for this route.
What pace multiplier should I use?
Use Fast (0.75×) if you are an experienced hillwalker with a light pack and good trail conditions. Use Normal (1.0×) for average fitness with a standard day pack on well-marked trails. Use Slow (1.25×) if you are a casual hiker, carrying a heavy pack, hiking with children or elderly companions, on unfamiliar terrain, or in poor weather. When in doubt, use Slow. Arriving early is always better than arriving after dark.
Should I bother with the descent correction at all?
Langmuir himself notes that over a full day it is usually left out, because the time gained on gentle ground tends to cancel the time lost on steep ground. It is worth applying when a route is lopsided: a long steep descent off a summit, or a gentle track that runs downhill for hours. Leave the elevation loss at 0 to skip it. Whatever you do, treat the answer as a minimum for a fit walker on a good path rather than an average, because that is what Naismith's Rule gives you.
What time should I start a hike?
For routes under 3 hours start by 10:00. For 3–6 hour routes start by 08:00. For routes over 6 hours start by 06:00. These are minimum recommendations for summer conditions in northern Europe. In autumn and winter, move start times 1–2 hours earlier due to shorter daylight. Always calculate your turnaround time before leaving and start early enough to complete the route with 1 hour of daylight to spare.
How does Naismith's Rule work for downhill hiking?
The original Naismith's Rule gives no specific adjustment for descent. It was designed as a conservative estimate where breaks during ascent account for descent time. Most modern adaptations subtract time for gentle descents and add time for steep descents. This calculator applies Langmuir's correction: subtract 10 minutes per 300 m of gentle descent (5 to 12 degrees), add 10 minutes per 300 m of steep descent (over 12 degrees). Pick the steepness that matches the ground and the calculator applies the right direction.
What is Tranter's correction for Naismith's Rule?
Tranter's correction adjusts Naismith's calculated time based on the hiker's fitness level. Fitness is determined by how long it takes to climb 300m over 800m distance. A fit person (45 minutes for the test climb) uses the standard Naismith time. Slower people multiply by more. A very fit person (15 minutes) can halve the Naismith time. This calculator uses simplified pace multipliers (Fast/Normal/Slow) that achieve a similar result.