How many calories does walking burn per kilometre?

Walking burns about 0.7 to 0.8 kcal per kilogram of body weight for every kilometre at normal speeds, which is roughly 44 kcal per km at 60 kg, 51 kcal at 70 kg and 66 kcal at 90 kg. Per mile, multiply by 1.6.

Distance-based numbers are useful because they ignore one of the messiest inputs, time. If you know how far you walked, a per-km figure gets you close without guessing how long it took.

Calories per kilometre by body weight and speed

The figures below divide the MET value of each walking speed, from the Compendium of Physical Activities, by the speed itself: kcal per km = MET x kg / km/h. This is the same calculation our walking calculator runs, just expressed per kilometre. Values are total calories, including resting burn.

Two things jump out. First, body weight scales the number almost linearly: 100 kg costs twice what 50 kg does. Second, the cheapest speed per kilometre sits around 4.8 km/h (3 mph). Very slow walking costs more per km because you spend more time moving at a fairly high baseline cost, and very fast walking costs more because walking becomes mechanically awkward close to running speed.

Calories per mile

For a mile, multiply the per-km figure by 1.609. A 70 kg (154 lb) walker at a moderate pace burns about 82 kcal per mile, and a 90 kg (198 lb) walker about 106 kcal. The common shorthand of "100 kcal per mile" fits people around 80 to 90 kg rather than everyone.

Extra calories above resting

The table shows total burn. To see what the walk added on top of sitting still, subtract one MET. At a moderate pace that brings the cost down by about 30%.

A useful mental rule: net walking cost is about half a kilocalorie per kg per km, so a 70 kg person adds about 36 kcal for each extra kilometre at a moderate pace. That is the number to use if your calorie target already includes your resting metabolism.

What changes the cost per kilometre

• Body weight, including anything you carry. A 10 kg backpack costs roughly what 10 kg of extra body weight does, often a little more.
• Gradient. Uphill walking can double the cost per km on steep ground. Downhill is cheaper but not free.
• Terrain. Sand, snow, grass and trails all cost more than pavement.
• Speed, mainly at the extremes. Between 4 and 6.5 km/h the cost per km stays fairly flat.
• Individual efficiency. Two people of the same weight can differ by 10 to 20% at the same speed.

How to use this number

1. 1Take your distance from a map or GPS app, which is more reliable than counting steps.
2. 2Multiply by your body weight and by 0.75 for a rough total, or by about 0.5 for the extra above resting.
3. 3Use the table above if you want speed-specific values.

For example, a 5 km walk at 80 kg is about 5 x 80 x 0.75, or 300 kcal in total, and about 200 kcal above resting.

Per kilometre, per step or per minute?

Calories per kilometre is the most stable way to think about walking, because cost per kilometre barely changes across normal speeds. Per-minute figures rise sharply with speed, and per-step figures depend on your stride length, which depends on your height. If you track walks with GPS, use distance. If you only have a step count, convert steps to distance first with roughly 0.41 x your height as step length, then apply the per-km figures.

For example, a 175 cm person has a step length of about 0.73 m, so 1,000 steps is about 0.73 km. At 70 kg and a moderate pace that is about 37 kcal per 1,000 steps in total.

Walking versus running per kilometre

Running costs roughly 1 kcal per kg per km across a wide range of speeds, against about 0.73 kcal per kg per km for moderate walking. So running a kilometre burns more than walking it, but the difference is smaller than most people expect, around a third more. The main advantage of running is time: you cover the distance two to three times faster. If time is not the limiting factor, longer walks can match a run for calories with far less impact on joints.

Treadmills and watches

Treadmill calorie displays usually use similar MET-based equations, sometimes adjusted for the weight you enter. If you never enter your weight, the display assumes a default, often around 70 to 80 kg, so lighter and heavier users get skewed numbers. Watches combine heart rate and motion and can be closer for some people and further off for others. Treat all of them as estimates within about 20%.

Hills, stairs and rucking

Gradient is the quickest way to raise the cost of each kilometre without walking faster. A moderate incline on a treadmill or a hilly route can add a third to a half to the per-km figures in the table, and steep climbs can double them. Carrying a loaded backpack, often called rucking, works in a similar way: the extra kilograms behave roughly like extra body weight. Both are good options for people who want more training effect from walking without moving up to running.