How the maths works

No black box. The calculator uses MET values, the standard measure from the exercise-science reference compendium, where one MET equals roughly one calorie per kilogram of body weight per hour. Easy flat walking runs around 3.8 METs, typical rolling-trail hiking about 5.3, hilly ground 6.5, and steep mountain days 7.5, with a day pack adding roughly 0.7 and a full multi-day load about 1.5 on top. Multiply the MET by your weight in kilograms and your hours moving, and that's your burn. It's an estimate with an honest margin of around 15 percent either way, because pace, fitness, cold and how rough the ground is all nudge it, but it's the same method behind every credible calculator, just with fewer fields between you and the answer.

What that looks like in real days

Take a 75kg hiker. A gentle two-hour flat amble with just a bottle: about 570 calories, a decent lunch. A five-hour day on rolling trails with a day pack: around 2,250, most of a day's normal eating spent before dinner. A seven-hour steep mountain round with a full pack: about 4,700, which is the quiet reason people come off big hill days shaking, headachey and inhaling the nearest chip shop. The gradient is doing the heaviest lifting in those numbers: moving from flat ground to a sustained climb can roughly double what an hour costs, which is also why the descent still charges you, less than the climb, but never nothing, because braking is work too.

Hiking versus walking versus running

Per hour, hiking sits between the two: roughly half again to double a flat walk, and about half a hard run. But the comparison flips on duration, because nobody runs for seven hours on a Saturday and plenty of people hike for that long, so a full hill day routinely out-burns anything you'd do in trainers on tarmac. It's the steady, hours-long nature of the burn that makes hiking quietly one of the biggest energy expenditures in ordinary life, and also what makes fuelling it a skill rather than an afterthought.

The part that matters: replacing it

Here's the practical takeaway hiding in your number. A 2,000-plus calorie day cannot be comfortably eaten back at dinner, and trying is how post-hike evenings end in headaches, wobbles and a fridge raid that still leaves you flat on Sunday. The fix is eating as you go: something small every hour of walking, around 100 to 200 calories at a time, weighted toward food that's dense, robust and eatable in weather, which is exactly what the best food for hiking list is built from and what the calorie-dense foods table ranks. It's also the honest reason a Phoenix Bar exists in this ecosystem: up to 557 calories in 120 grams means one bar quietly covers an hour-plus of hill walking from a jacket pocket. On multi-day trips the arithmetic compounds, since you'll burn more than you can carry the appetite to eat, and managing that deliberate deficit is covered in the hiking nutrition guide and the food planning sections of the multi-day kit list. And if you're hiking partly for the energy balance, the same numbers serve you fine; just know the trail rewards people who fuel the effort either way.

Frequently asked questions

How many calories does hiking burn per hour? Between 350 and 600 for most adults, driven by weight, gradient and pack. Flat easy walking sits nearer 300; steep loaded mountain ground can pass 700.

How many calories does hiking burn per mile? Roughly 80 to 120 for most people on typical trails, rising well past 150 per mile on sustained steep climbs. Hours are a more reliable basis than miles because terrain changes what a mile costs.

Does a heavy pack really burn more? Yes, meaningfully: a full multi-day load adds in the region of 100 or more calories per hour for an average adult versus walking unladen, which is one more argument for the lightest pack you can sensibly build.

Do you burn calories hiking downhill? Yes. Descending burns less than climbing but far more than resting, because your legs are braking your bodyweight the whole way down, which is also why big descents leave muscles sorer than the climb did.

How much should I eat on a hike? Little and often beats a big stop: around 100 to 200 calories per hour of walking, from dense, pocketable food, starting before you feel the dip. The full approach lives in our hiking nutrition guide.

Written by James Frost, founder of Flaming Phoenix. We feed hikers, ultra runners and expedition teams in 19 countries, and this calculator exists because "how far is it in flapjacks" is a genuinely useful question. Last updated July 2026.