Backpacking Pack Weight Calculator
Enter the gear, food, water, and consumables you expect at the start of your heaviest leg. The calculator shows that departure weight, the full-trip food total, and how many food days fit your own comparison target.
Heaviest departure pack weight29.91 lb (13.57 kg)
- Pack weight as a percentage of body weight
- 17.59%
- Food needed for the full trip
- 12.25 lb (5.56 kg)
- Food in the heaviest carry
- 7.00 lb (3.18 kg)
- Water weight at departure
- 4.41 lb (2.00 kg)
- Weight after one food day
- 28.16 lb (12.77 kg)
- Maximum food-carry duration at target (days)
- 6.3
- Amount over or under target
- 4.09 lb (1.86 kg) under target
Food weight is treated as evenly allocated per equivalent day.
Weight after one food day does not assume any water or fuel consumption.
How to use this calculator
- Enter your body weight and a comparison percentage that you want to use for planning.
- Enter base weight, excluding food, water, consumable fuel, and worn clothing.
- Enter total trip length and the longest interval between resupply points, using half days where appropriate.
- Enter food per day, the largest expected departure water amount, and consumable fuel or supplies.
- Read the heaviest departure weight and adjust the food carry or resupply plan if needed.
How backpack weight is calculated
Backpacking weight changes through a trip, so the useful planning point is often the start of the heaviest leg. This calculator treats base weight as gear that stays with you, then adds the food needed before the next resupply, departure water, and consumable fuel or supplies. Worn clothing is not part of base or carried pack weight.
Let B be base weight in pounds, D total trip days, C the smaller of the longest food carry and D, F food weight per day, W water liters, and G consumables in ounces. Water weight is U = 2.20462 × W, and consumables weigh E = G ÷ 16 pounds. The heaviest departure pack is:
Q = B + (C × F) + U + E
Total food for the trip is D × F. The pack percentage is 100 × Q ÷ M, where M is body weight. The percentage is a comparison point, not a rule about what is safe or comfortable for every person.
Planning the food-carry limit
For a chosen target percentage P, the target pack weight is A = M × P ÷ 100. After base weight, water, and consumables are set aside, the remaining allowance is divided by daily food weight: max(0, (A − B − U − E) ÷ F). The calculator rounds this result down to a tenth of a day so the displayed carry does not claim more capacity than the target permits.
Food weight per day and the longest resupply gap usually move the result most. A shorter gap removes food from the heaviest carry without changing base weight. Departure water can have the same effect as several meals, especially on dry sections, so use the largest amount you realistically expect to leave a source with.
What this calculator leaves out
This is component accounting, not a calorie plan or a safety assessment. It does not predict calorie needs, changing water availability, fuel burn, emergency reserves, pack fit, terrain, weather, or fatigue. Include required containers, bear-resistant storage, food packaging, and carried trash in the input where they belong; empty canisters and containers belong in base weight.
Worked example
For a 170 lb hiker with an 18 lb base weight, a seven-day trip, a four-day longest carry, 1.75 lb of food per day, 2 liters of water, and 8 oz of consumables, food on the heaviest leg is 4 × 1.75 = 7.00 lb. Water weighs 2 × 2.20462 = 4.41 lb and consumables weigh 8 ÷ 16 = 0.50 lb.
The heaviest departure pack is 18 + 7 + 4.40924 + 0.5 = 29.91 lb, or 13.57 kg. That is 17.59% of body weight. At a 20% target, the 34 lb target allows a maximum food carry of floor((34 − 18 − 4.40924 − 0.5) ÷ 1.75, 0.1) = 6.3 days.
Common questions
What counts toward backpacking base weight?
Base weight is the gear you carry that remains after consumables are used: pack, shelter, sleep system, clothing carried, cookware, tools, and empty containers. It excludes food, water, consumable fuel, and worn clothing. Include an empty fuel canister or water bottle in base weight, then enter only its contents as a consumable.
What is the difference between base weight and total pack weight?
Base weight is the relatively fixed gear portion. Total pack weight adds food, water, fuel, and other consumables that vary during the trip. The total is normally greatest when leaving a trailhead or resupply with the most food and water.
How much does one liter of water weigh?
For trip planning, one liter of water weighs about one kilogram, or 2.20462 pounds. The actual density changes slightly with temperature and dissolved material, but that difference is too small to matter for ordinary pack-weight planning.
How should partial first and last days be entered?
Enter equivalent food days rather than calendar dates. For example, a trip that needs a half day of food on the first day, five full days, and a half day on the last day can be entered as six days. Use the same approach for a short final carry after the last resupply.
Do resupply stops reduce maximum pack weight?
Yes. A resupply stop reduces the number of food days carried at once, which lowers the heaviest departure weight. It does not change base weight, and a remote section may still require more water or fuel, so compare the weight at each leg rather than food days alone.
Is 20 percent of body weight a strict backpack limit?
No. It is a personal comparison target, not a medical or universal safety limit. Comfort and risk depend on conditioning, injury history, pack fit, terrain, weather, pace, and experience as well as the number on a scale.