ROUTE TIME ESTIMATOR
Planning a walk is about more than knowing how far you’re going. A route that looks short on a map can take considerably longer when it includes steep climbs, difficult terrain or a heavy pack.
Naismith’s Rule gives you a simple starting point for estimating how long a walking route might take. It combines the distance you need to walk with the amount of ascent on the route to produce an estimated walking time.
Use the estimator below to get a quick idea of how long your route could take before you set off.
Estimate Your Route Time
Enter your route distance and total ascent below. The estimator will use Naismith’s Rule to calculate an approximate walking time.
⏱️ Naismith’s Route Time Estimator
Calculate your expedition route transit times using traditional UK mountain navigation formulas, optimized for youth groups and heavy packs.
💡 Naismith’s Rule assumes steady movement without long rest breaks. Always add extra time for lunch stops, kit adjustments, or complex navigation checkpoints!
What Is Naismith's Rule?
Naismith's Rule is a traditional method of estimating walking time in the hills and mountains.
The basic rule assumes a walking speed of 4.8 kilometres per hour (3 miles per hour), with an additional 30 minutes added for every 300 metres (1,000 feet) of ascent.
For example, a route of 9 kilometres with 600 metres of ascent would have a basic walking time of around 1 hour 53 minutes for the distance, plus another hour for the climbing. That gives an estimated time of approximately 2 hours 53 minutes.
The rule is deliberately simple. Its value is that it gives you a useful starting point for route planning without requiring a complicated calculation.
How Accurate Is Naismith's Rule?
Naismith's Rule is an estimate, not a promise of how long your walk will take.
Your actual walking time can be affected by many things that the basic calculation doesn't account for. Terrain, weather, navigation, fitness, pack weight, stops and the experience of the group can all make a difference.
A rocky mountain path, for example, may take considerably longer than a smooth trail of the same distance and ascent.
Similarly, a group walking with young people may move at a very different pace from a fast individual walker.
Use It as Part of Your Route Planning
Naismith's Rule works best when it is used alongside the rest of your route planning rather than on its own.
Look at the terrain, check the weather forecast, consider the fitness and experience of everyone taking part and think about where you may want to stop.
It's also worth allowing some extra time for navigation, breaks, photographs, food and unexpected delays.
If you're planning a longer or more demanding route, don't build your plans around the absolute minimum estimated time. Having some spare time gives you much more flexibility if conditions change.
A Simple Example
Imagine you're planning a 12-kilometre walk with 450 metres of total ascent.
The distance alone would take about 2 hours 30 minutes at Naismith's assumed walking speed.
The 450 metres of ascent adds another 45 minutes.
That gives an estimated walking time of approximately 3 hours 15 minutes before allowing for stops and other delays.
Your actual route could take longer depending on the terrain and conditions, so this figure should be treated as a planning estimate rather than an exact finish time.
Remember the Descent
Naismith's original rule is primarily concerned with distance and ascent. It doesn't give a separate allowance for descending.
That doesn't mean downhill walking is always easy. Steep, rocky or slippery descents can be tiring and may require considerably more care than the calculation suggests.
When planning a route, look at the whole route profile rather than relying solely on the estimated time.
Plan for the Real Route
A calculator can give you a useful number, but the map tells you what that number actually means.
Look at the route, identify steep sections, check the terrain and consider the people who will be walking it. If the route includes difficult ground or challenging navigation, allow additional time.
Good route planning isn't about predicting the exact minute you'll arrive. It's about having a realistic idea of how long the journey could take and giving yourself enough time to deal with the unexpected.
Keep Building Your Navigation Skills
Once you've estimated your route time, explore our navigation and route-planning guides to learn more about choosing routes, measuring distance, using maps and planning for different conditions.
The better you understand your route before setting off, the more confidently you can manage it when you're outdoors.