How many miles is 50k?
A 50k is 31.1 miles, or exactly 50,000 metres, and it is the shortest distance that counts as an ultramarathon. Walked, it is ten hours on foot. Here is what it is in steps, minutes and calories, and why it is not as far as it sounds.
The numbers
50.0 km · 31.1 miles, in steps
| A child, 1.2 m (3 ft 11 in) | about 100,600 steps |
| 1.6 m (5 ft 3 in) | about 75,500 steps |
| 1.7 m (5 ft 7 in), the average adult | about 71,000 steps |
| 1.8 m (5 ft 11 in) | about 67,100 steps |
| 1.9 m (6 ft 3 in) | about 63,600 steps |
| A giraffe, 5.5 m (18 ft) | no idea, sorry |
Step length is about 41% of height. Give or take 10% for how you walk.
How long it takes to walk
| A stroll, 4 km/h | 12 h 30 min |
| A normal walk, 5 km/h | 10 h |
| A brisk walk, 6 km/h | 8 h 20 min |
Walking without stops, on level ground.
Calories, by body weight
| 55 kg (121 lb) | about 1,753 kcal (2,330 incl. resting) |
| 70 kg (154 lb) | about 2,231 kcal (2,966 incl. resting) |
| 85 kg (187 lb) | about 2,709 kcal (3,602 incl. resting) |
| 100 kg (220 lb) | about 3,187 kcal (4,237 incl. resting) |
The walk's own cost at 5 km/h. The second number adds what you would have burned sitting still, which is what some fitness trackers show.
Try your own distance
Steps
about 71,000
63,900 to 78,100 depending on your stride, about 0.70 m a step at this height.
Distance
50.0 km · 31.1 miles
Time on foot
10 h
at 5 km/h, no stops
Calories
Depends on your weight more than anything else. Enter it to see an estimate.
That is 9/10 of the way to Everest Base Camp.
How many steps is a 50k?
About 71,000 steps for an adult of average height, from roughly 75,500 at 1.6 m to 63,600 at 1.9 m, because a walking step is about 41% of your height and a 1.7 m adult covers about 0.70 m a step. Your own count can sit 10% either side of the figure for your height.
How many calories does walking a 50k burn?
About 2230 kcal for a 70 kg (154 lb) adult at a normal pace, from roughly 1755 kcal at 55 kg (121 lb) to 3185 kcal at 100 kg (220 lb). Body weight decides most of it. That is the walk’s own cost above sitting still. Some fitness trackers report the total including what you would have burned anyway, which comes out about a third higher. The figures come from a model of walking energy cost built on height, weight and speed, tested within a few percent of measured values across body sizes.
What a 50k is
Fifty kilometres, exactly 50,000 metres, which is 31.069 miles. It is the first distance beyond the marathon on the World Athletics list and the entry point to ultramarathons, which are simply any race longer than 42.195 km. Most 50k events are on trails rather than roads, and many are walked in part by everyone in them, because ten hours of running is not what most bodies do. Walked throughout at a normal pace it is ten hours, and on a trail with climbs, more. It is also close to the distance of the Everest Base Camp trek from Lukla, which the numbers below spell out.
Walk the distance first
A race is a day. The way to be ready for it, and the way to enjoy the same distance without a start line, is to walk it in pieces on the days you already have. A 50k is 9/10 of the way to Everest Base Camp, and reTrek is built for exactly that: pick a route, Everest Base Camp is free, and your everyday steps carry you along it with a short film waiting at each milestone. Something to look forward to. Progress you can see.
Walk it with a friend and pool your steps, or race them there, and find out which of you skips fewer evenings.
Other race distances
Sources: Road running disciplines and standard distances, World Athletics · Energy expenditure during level human walking, Ludlow and Weyand, Journal of Applied Physiology, 2016