How many calories does walking burn?
The useful way to think about walking is per unit of distance, not per step. Covering a kilometre on the flat costs roughly half your bodyweight in kilograms, expressed in kilocalories. A 70 kg (155 lb) person spends about 35 kcal per kilometre, or about 56 kcal per mile.
The cost of a kilometre
| Bodyweight | Per kilometre | Per mile | 5 km (3.1 miles) | |
|---|---|---|---|---|
| 55 kg | 120 lb | ~28 kcal | ~44 kcal | ~140 kcal |
| 70 kg | 155 lb | ~35 kcal | ~56 kcal | ~175 kcal |
| 85 kg | 185 lb | ~43 kcal | ~68 kcal | ~215 kcal |
| 100 kg | 220 lb | ~50 kcal | ~80 kcal | ~250 kcal |
In imperial terms the rule of thumb is about 0.36 kcal per pound per mile. Bodyweight does nearly all the work in that calculation, because walking is essentially the job of moving a mass along a horizontal line. What is striking is how little else shifts the number — with one large exception.
Incline is the biggest multiplier by far
Climbing costs roughly 0.01 kcal per kilogram per vertical metre. That looks trivial until you notice how quickly vertical metres accumulate on even a mild gradient.
A 5% slope gains 50 m of height per kilometre travelled. For a 70 kg (155 lb) walker that is 0.01 × 50 × 70 ≈ 35 kcal of climbing on top of the 35 kcal the kilometre already cost — near enough to double it.
| Gradient | Climb per km | 70 kg (155 lb), per km |
|---|---|---|
| Flat | 0 m | ~35 kcal |
| 3% | 30 m | ~56 kcal |
| 5% | 50 m | ~70 kcal |
| 10% | 100 m | ~105 kcal |
Nothing else in walking comes close. Coming back down does not refund the climb either — descending costs slightly more than flat ground, not less — so an out-and-back over a hill is dearer than a flat loop of the same length. If you want a walk to cost more, the lever is terrain rather than effort: a hilly 5 km (3.1 miles) can cost what a flat 8 km (5 miles) does, in less time.
Why pace barely matters on the flat
Walking faster does not change the physics much. Moving a given mass a given distance takes roughly a fixed amount of work, so the cost per kilometre is nearly constant between about 3 and 7 km/h (2–4.5 mph). You finish sooner and the burn per minute is higher, but the total for the route is similar.
Two things break that. Above roughly 7–8 km/h (4.5–5 mph) walking turns inefficient: the pendulum mechanics that make it cheap stop working, cost per kilometre climbs steeply, and most people spontaneously break into a run, which is genuinely cheaper than walking at that speed. And on a hill pace matters considerably, because the climbing work is unavoidable. Flat walking is forgiving of pace; uphill walking is not.
The gross-versus-net twist
Pace does change the headline figure, but not in the direction people expect. Part of any burn during a walk is resting energy you would have spent anyway — and a slow walk spends more minutes spending it.
For a 70 kg (155 lb) person with a resting rate near 1,700 kcal/day, about 1.2 kcal/min, one kilometre looks like this:
- At 7 km/h (8.5 min): ~35 kcal walking + ~10 kcal resting = ~45 kcal gross
- At 4 km/h (15 min): ~35 kcal walking + ~18 kcal resting = ~53 kcal gross
The slower walk shows the bigger number while doing the same quantity of actual walking. That resting share is not extra; it was always on the books. The same gross-versus-net problem in step counts is the main reason walking estimates get inflated, and it is why Caldown keeps active and resting energy as separate figures rather than summing them.
Carrying load, and where you carry it
Extra mass costs roughly what it would if it were you. A 10 kg (22 lb) pack on a 70 kg (155 lb) walker adds about 14%, or some 5 kcal per kilometre. A pushchair, a toddler or a full rucksack genuinely moves the figure.
Where the weight sits matters more than how much of it there is. Mass on the feet and ankles is swung back and forth with every stride and costs several times what the same mass costs on your back; carrying in the hands sits somewhere between. Weighted ankle straps are an efficient way to burn slightly more and an inefficient way to keep your knees.
Surface works on the same principle: grass and loose gravel add perhaps 10–20%, dry sand can approach double, fresh snow more.
What to do with the figure
Walking is where estimates are misused more often than they are wrong. Wrist trackers infer walking from arm motion, which is only loosely coupled to what your legs are doing — push a trolley or hold a phone and the estimate drifts, as Apple Watch calorie accuracy sets out. Distance and bodyweight will usually get you closer than heart rate will.
Either way it is a small input to a larger sum. Whether the kilometres show up on the scale depends on the day’s total against your maintenance calories, and on what your body burns before you move at all. Walking’s real advantage is not the arithmetic: it is one of the few activities that neither raises appetite sharply nor costs a day of recovery, so the kilometres repeat.
General information, not medical advice.