How Much Food for a Hike? Turning Calories Into a Food Bag
Running out of food on a hike is miserable, and running low is quietly dangerous: a hungry hiker is slower, colder and makes worse decisions late in the day. Carrying far too much is the opposite problem, a heavy bag of snacks that comes home uneaten. A calorie estimate turns this into something you can plan. This guide takes a hypothetical two-day trip through the Hiking Calorie Burn Calculator and the Backpack Weight Calculator, and turns the result into grams of food.
The trip
A 75 kg hiker plans an overnight trip on a rocky trail (terrain factor 1.2):
- Day 1: 9 km climbing at an average 6% grade, at 3 km per hour, then 9 km descending to camp at 4 km per hour.
- Day 2: 7 km climbing at 6%, then 7 km down to the trailhead.
Climbs and descents are run as separate legs, because the calorie equation treats them very differently; see how the Pandolf equation works.
Step 1: the pack
The load matters to the calorie estimate, so start with the pack. With a 7 kg base weight (pack, shelter, sleeping bag and mat, stove, clothing, first aid), 1.6 kg of food, 2.5 litres of water and 0.25 kg of fuel, the Backpack Weight Calculator gives:
- Consumables: 4.35 kg.
- Total pack: 11.35 kg, 15.13% of body weight, inside the calculator's 20% guideline (a rough guide, not a medical limit).
- Base weight class: lightweight.
By the second morning, with half the food eaten and a little fuel used, the same calculation with 0.8 kg of food and 0.15 kg of fuel gives 10.45 kg.
Step 2: what the walking costs
| Leg | Pack | Time | Rate | Calories |
|---|---|---|---|---|
| Day 1 climb, 9 km at 6% | 11.35 kg | 3 h | 406 W | 1,047 kcal |
| Day 1 descent, 9 km | 11.35 kg | 2.25 h | 112.5 W (floor) | 218 kcal |
| Day 2 climb, 7 km at 6% | 10.45 kg | 2.33 h | 402 W | 807 kcal |
| Day 2 descent, 7 km | 10.45 kg | 1.75 h | 112.5 W (floor) | 169 kcal |
Walking costs about 1,265 kcal on day 1 and 976 kcal on day 2. Two things make these minimums rather than exact figures. The descent rows sit at the calculator's floor, standing metabolism, because the 1977 equation under-counts downhill effort; a real descent costs more. And the equation is an estimate for an average person; your own efficiency, fitness and the conditions on the day will move it.
Step 3: add your ordinary daily needs
This is the step most people miss. The calculator estimates the energy of the walking, the five or so hours you are on the move. You also need the energy you would use on any ordinary day: to sleep, sit in camp, keep warm overnight and digest your meals. That baseline depends on your size, age, sex and health, and is not something this site calculates. Your total for a hiking day is roughly your normal daily intake plus the hiking figure, and more if it is cold.
In practice, people on multi-day trips often eat noticeably more than at home and still come back lighter. On a one or two night trip that is not a problem. On longer trips, carrying too little food day after day leads to fatigue and poor recovery.
Step 4: turn calories into grams
Food weight depends on energy density, the calories in each gram. Fat carries about 9 kcal per gram and carbohydrate and protein about 4, so foods high in fat (nuts, nut butter, cheese, chocolate) are energy-dense, while fresh fruit and anything watery are not. Many backpackers aim for a food bag that averages somewhere around 4 to 5 kcal per gram across everything in it.
Just to cover the hiking part of day 1, at 4 kcal per gram, needs roughly 320 g of food; at 5 kcal per gram, about 250 g. For day 2's walking at 4 kcal per gram, about 240 g. On top of that goes the food for your ordinary daily needs: breakfast, dinner and the rest of what you would normally eat.
That is why the 1.6 kg of food in the pack above is reasonable for a two-day trip: it covers dinner, breakfast, lunches and trail snacks, with something spare. If your food bag is coming out much heavier than about a kilogram per day for ordinary trips, look for watery or bulky items; if it is much lighter, check you are not underestimating the trip.
What to pack
- Trail snacks you will actually eat when tired. Appetite often drops on hard days and at altitude. Test foods on day hikes first.
- Something salty. You lose salt through sweat, especially on warm days. Salted nuts, crackers, cheese and savoury snacks help, and pairing salt with water helps avoid the low-sodium problem that comes from drinking lots of plain water.
- A real dinner. A hot meal at camp matters for warmth and morale as much as calories.
- A spare. Carry an extra snack bar or two beyond your plan, for a delay, a cold night or a companion who ran short. The ten essentials include extra food for this reason.
- Packaging stripped down. Repack into reusable bags where you can, and carry out every wrapper.
Store food as the land manager requires. In some places that means a bear-resistant container or hanging food; in others, simply keeping it away from your tent. Check the rules for where you are going.
Day hikes
The same approach works for a day hike, with simpler numbers. Estimate the walking with the calculator, eat a normal breakfast, and carry enough snacks and lunch to cover the walking figure with a margin. On a day hike, carrying a few hundred grams more than you need is a small price for never running out. Little and often is better than one large lunch: small snacks every hour keep energy steadier, and long lunch stops make you cold.
Water goes with food
Dehydrated meals need water to cook, and dry snacks are easier to eat with water. If you are planning water from the Water Needs Calculator, add what your cooking needs on an overnight trip, and check the water sources near camp before relying on them. Always treat water from natural sources.
What this does not tell you
These are planning estimates. They are not a diet plan, a medical calculation or a guide to managing a health condition. If you have diabetes or another condition that affects how you plan food and exercise, talk to your doctor before a long or hard trip. If you are new to multi-day trips, a slightly heavier food bag is the safe mistake to make.
Work out the pack, estimate the walking leg by leg, add your ordinary needs, convert to grams with a realistic energy density, then pack a little extra. It takes ten minutes the night before, and it means the last climb of the trip is powered by something more than the memory of breakfast.