Michael Turner
Baseweight targets: ultralight <7 kg (choose ~30–45 L rucksack), traditional 7–12 kg (choose ~50–65 L), expedition loads >12 kg (choose ≥70 L). Match capacity to the intended baseweight rather than trip length alone.
Measure torso from the C7 vertebra to the top of the iliac crest: common fits are short 40–46 cm, medium 46–51 cm, long 51–56 cm. Measure hip circumference at the widest point of the pelvis; select a hipbelt that matches that measurement so load transfers to hips rather than shoulders.
Typical gear-volume ranges to estimate required liters: down sleeping bag 5–12 L, synthetic bag 8–15 L, 1–2 person tent 8–20 L, insulated sleeping pad 2–6 L, layered clothing 8–15 L, cook system + fuel bottle 3–6 L, electronics + repair kit 2–6 L. Food volume converts roughly to weight: 0.6–1.2 kg per day (freeze-dried lower, heavy fresh food higher). Water is 1 L per kg; plan 1–3 L carried depending on resupply points and filtration options.
Use a simple calculation: sum non-consumable gear volumes, add expected food/water volume, then include a 15–30% margin for bulky or wet items. Example: shelter 12 L + sleep 10 L + clothing 12 L + cook 5 L + electronics 4 L = 43 L; add food/water 4–6 L → 47–49 L; +20% margin → ~60 L chosen.
Volume-saving strategies: replace double-wall tents with single-wall, swap heavy synthetic layers for down where appropriate, use compression sacks for sleeping gear, and plan food to reduce days of carry. For cold-season trips allocate an extra 15–30 L for insulation, heavier stove/fuel and bulk safety gear.
Rucksack Volume Recommendations by Trip Length and Load
For a typical 3-season 3–7 night outing, select a 50–65 L rucksack when baseweight (shelter, sleep system, clothing, stove, cookset) is 6–9 kg (13–20 lb); expected total loaded weight then falls between ~12–18 kg (26–40 lb).
Volume quick-reference
Day trips: 15–30 L for loads under 3–6 kg (6–13 lb) – enough for water, light food, rain jacket, first-aid.
Weekend (1–2 nights): 35–50 L for baseweights of 4–7 kg (9–15 lb) and one or two extra layers, small stove and 1–3 days of food.
Multi-night (3–7 nights): 50–65 L for standard 3-season gear and 3–7 days of consumables; ultralight setups can fit into 35–45 L if baseweight ≤6 kg.
Extended trips or cold-season travel: 65–85 L when adding heavy sleeping systems, thicker clothing, fuel and group gear; add 10–25 L more for technical gear (crampons, rope) or extended food caches.
Expeditions & mountaineering: 85+ L for sustained glacier travel, snow-specific equipment and large fuel/food loads.
Fit and load guidelines
Measure torso from C7 vertebra to the top of the iliac crest to pick the correct frame height; choose a hipbelt size that fits your hip circumference so the hips bear ~80–90% of the load. Aim for loaded weight ≤20–25% of body mass for long days; short pushes can tolerate up to ~30% for fit hikers. Example: a 70 kg person is most comfortable carrying 14–17.5 kg on extended days.
Plan volume around baseweight plus consumables: food ≈0.5–0.9 kg per day, water 1 L ≈1 kg (typical 1–2 L/day unless resupply frequency or climate changes). Reserve 10–20% extra internal volume for off-trail gear, rain gear and packaging. If hauling group items or a bear canister (adds ~5–10 L and 0.5–1.5 kg), size up one category.
When choosing, test a fully loaded rucksack in-store or with a trial hike. Compression sacks and external lash points reduce required volume but do not replace adequate frame and hipbelt fit. If torn between two sizes, pick the smaller if your goal is lightweight travel; pick the larger if you expect cold conditions, heavy fuel loads or shared gear.
Volume by trip duration: day (<10L), weekend (20–35L), 3–7 days (40–65L), extended (70+L)
Use these volume targets as a rule: day – <10 L; weekend – 20–35 L; 3–7 days – 40–65 L; extended – 70+ L.
- Day (<10 L)
- Loaded weight: 0.5–2 kg.
- Typical contents: 0.5–1 L water, wind/rain shell (compresses to 0.5–1 L), snacks, phone + power bank, compact first-aid, map, small camera. No sleeping system.
- Recommended features: lightweight shoulder straps, minimal hip support, hydration sleeve or side pockets.
- Weekend (20–35 L)
- Loaded weight: 3–6 kg for fastpacking; 6–9 kg for comfort setups.
- Typical contents: 1–2 L water, 1-person bivy or ultralight tarp (6–12 L), 20–40 L sleeping quilt or compact synthetic bag (compressible), lightweight stove + 0.5–1 L fuel, 1–2 days of food, basic repair kit and layers.
- Recommended features: modest hipbelt, modest frame or stiff backsheet, lid pocket, external compression straps for a rolled sleeping pad.
- 3–7 days (40–65 L)
- Loaded weight: 7–12 kg for ultralight loads with resupply; 12–18 kg for full-carry including noncompressible items.
- Typical contents: 2–3 L water capacity, 3-season tent (6–15 L), sleeping bag/quilt (8–12 L), insulated clothing, cook system + fuel (4–8 L), food for duration (estimate 0.6–1.0 kg/day), bear canister if required.
- Recommended features: articulated hipbelt, adjustable torso, hip pockets, daisy chains for external attachment, internal frame or aluminum stays for heavier loads.
- Extended (70+ L)
- Loaded weight: 12–25+ kg depending on food carry and group gear.
- Typical contents: large tent or group shelter, multi-day fuel, extra insulation for cold nights, climbing or winter kit, extended first-aid/repair supplies, bulk food or cache equipment.
- Recommended features: robust internal frame, wide padded hipbelt with load lifters, full-access zips, dedicated sleeping compartment, reinforced attachment points for skis/poles/panniers.
Adjust these volumes by conditions and style:
- Cold-season trips: add 15–30 L for insulation and bulkier sleep systems.
- Photography or technical gear: add 8–20 L depending on lenses and cases.
- Resupply strategy: food for 1–3 days only reduces required volume; plan accordingly.
Item-volume examples to estimate required capacity:
- 1-person tent compresses to ~6–15 L.
- Synthetic 0°C sleeping bag: ~8–12 L; down 0°C: ~5–9 L.
- Sleeping pad stowed externally saves internal liters but increases wind profile.
- Stove + small fuel canister: 3–6 L depending on model.
Tip: test-load your chosen rucksack with real gear and weigh the result; if loaded weight exceeds comfortable carry for planned daily mileage, choose the next size up only if extra volume will be regularly filled. For lightweight sun shelter options see best vintage beach umbrella. For guidance on modular or removable components in other gear categories consult resources like are smeg fridge freezer doors removable.
Calculate liters from your baseweight: weigh core gear then add food, water and contingencies
Recommendation: Weigh core items (baseweight in grams), total the packed volumes of bulky items (manufacturer L spec or measured compression sack volume), add food volume (0.4–0.8 L per day typical), add required water liters, then add 10–20% volume margin; select a carrying volume 5–10 L higher than that sum.
Weighing procedure: place only the items you will carry on every outing on a kitchen or postal scale and record grams. Categories to include: shelter (body, poles, stakes), sleeping system (bag + pad if stowed), insulation layers, cook kit & stove, footwear (if carried), electronics & batteries, toiletries, repair kit. Exclude consumables (food, water, fuel) for the baseweight total.
Use packed-volume specs where available. Typical compressed-volume ranges (packed): down sleeping bag 5–8 L; synthetic bag 8–16 L; tarp/tarp-tent 3–8 L; lightweight freestanding tent 10–18 L; single-wall pyramid/one-person tent 5–12 L; puffy jacket 3–8 L; midlayer 2–6 L; cook kit 1–3 L; stove & fuel container 0.5–2 L; miscellaneous small items 1–4 L. Sum these to get base bulk volume.
Food conversion: high-calorie dense food = ~250–350 g/day (~0.3–0.5 L/day); average food = ~400–700 g/day (~0.5–0.9 L/day); heavy resupply-poor or cold conditions = 700–1,000+ g/day (~0.9–1.3+ L/day). Convert planned days of food into liters and add to volume total.
Water planning: carry liters directly (1 L = 1 L; 1 L = 1,000 g). Short resupply sections commonly require 0.5–2.0 L; dry or exposed sections commonly require 3–5 L or more. Add the full liters you will start with to the volume budget.
Contingency margin: add 10–20% of the summed liters for rain gear, extra insulation, trash, bear canister space, or unexpected items. If packability is poor (bulky clothing, uncompressible fuel bottles), add a fixed 3–6 L beyond the percentage.
Examples: 1) Ultralight setup: sleeping bag 6 L + tarp 5 L + puffy 4 L + cook kit 1.5 L + misc 2 L = 18.5 L; 3 days food at 0.5 L/day = 1.5 L; water 1.5 L = 1.5 L; 15% margin = 3.1 L → total ≈ 24.6 L → pick 30 L. 2) Standard multi-night: bag 10 L + tent 14 L + puffy 6 L + cook kit 2 L + misc 4 L = 36 L; 5 days food at 0.7 L/day = 3.5 L; water 2 L = 2 L; 12% margin = 5.1 L → total ≈ 46.6 L → pick 50–55 L.
Final rule: base your volume on summed packed volumes plus consumables and a margin; round up to the next common size (e.g., 30, 40, 50, 65 L) to allow room for awkward items and minor additions.
Match load carrier to your body: measure torso length and hip belt circumference for proper fit
Measure torso length from the C7 vertebra (most prominent neck bone when you tilt your head forward) down to the top of the iliac crest (highest point of the hip bones). Record in centimetres and inches; use the following sizing as a baseline: Short <41 cm (<16″), Regular 41–46 cm (16–18″), Long 46–51 cm (18–20″), Extra‑long >51 cm (>20″).
Measure hip belt circumference by wrapping a tape measure around the top of the iliac crest where the hip belt will sit–stand upright, feet together, tape snug but not compressing. Typical hip sizes: Small 71–81 cm (28–32″), Medium 81–97 cm (32–38″), Large 97–112 cm (38–44″).
Measurement technique: have a partner locate C7, mark it, then mark the top of the iliac crest on both sides and measure along the spine between marks. Repeat twice and use the larger value if results differ by >1 cm. Take hip measurement wearing the underwear or shorts you will use while loaded.
Interpretation and adjustability: fixed harnesses match the sizing above; adjustable harnesses commonly offer 3–8 cm (1–3″) of range. If your torso falls on a boundary, pick the shorter harness for heavy loads and the longer one for minimalist/light loads. Hip belts often come with removable or exchangeable pads that change fit by ±2–4 cm.
Fit cues once loaded: hip belt centre should sit squarely on top of the iliac crest and carry ~80–90% of the weight; you should be able to slide a flat hand (palm) between shoulder and shoulder strap when the belt is tightened and load is shifted to hips; load lifters set to about 30–45° from the horizontal.
Common problems and fixes: persistent shoulder pressure = torso too long or hip belt too low; lower‑back pain = hip belt riding too high or too small; pack feels unstable or sways = hip belt too loose or too large; ribs or hip pad chafing = reposition belt ±3 cm or try a different pad shape. If adjustments fail, try a different frame length or model with a wider adjustment range.
Adjust capacity for season and shelter type: summer vs winter, tent vs tarp vs hammock
Add ~10–30 L for winter compared with summer; choose +0–10 L for a tarp setup versus a freestanding tent in summer, and +5–20 L for a hammock system (larger delta in cold conditions).
Typical extra-volume drivers (with rough liter costs): winter sleeping bag 6–12 L (vs summer 3–6 L), insulated jacket 4–8 L, thicker sleeping pad 2–6 L, bulk clothing 5–12 L, fuel + stove carry 1–4 L, heavier shelter components (snow stakes, pole extensions) 1–4 L. Compression sacks usually cut visible volume by 20–40% for down items but do not remove the weight penalty.
Shelter type volume implications: a lightweight freestanding tent body and poles commonly occupy 6–12 L compressed; a tarp (with ridgeline + stakes) often packs to 2–6 L but requires extra guyline and stakes that add 0.5–2 L; a hammock system (hammock + suspension + tarp + underquilt) generally needs 8–18 L depending on insulation choices. In cold weather a tarp or hammock usually forces larger sleep insulation, erasing some of their volume advantage.
| Shelter system | Summer delta (L) | Winter delta (L) | Practical note |
|---|---|---|---|
| Freestanding tent (single-person, lightweight) | Baseline 0–+5 | +10–+20 | Bulky poles add space but simplify setup; good for wet/cold sites |
| Tarp (single tarp + groundsheet or bivy) | -5–0 | +5–+15 | Lowest shelter volume in warm, dry conditions; cold requires larger sleep kit |
| Hammock (with underquilt and tarp) | +5–+15 | +15–+30 | Comfortable off-ground but underquilts and suspension add bulk in cold |
| Tarptent / hybrid shelters | -2–+3 | +8–+18 | Middle ground: lighter than tent, more shelter than tarp; winter models bulk up |
Practical adjustments: for a summer 3-day solo baseline of 40 L, expect ~35–45 L with a tarp, ~45–55 L with a hammock (summer insulation), and ~55–70 L for the same trip in winter with a tent. Prioritize low-bulk insulation (higher fill-power down, synthetic with packs that compress well) and replace bulky garments with layered low-bulk pieces to limit added liters. After selecting season and shelter, simulate a loaded bag and confirm volume physically rather than relying only on itemized estimates.
Reduce required size with compression straps, stuff sacks and external carry points
Use compression straps plus a set of 3–5 stuff sacks to shrink carried volume by 15–40% and move 3–10 L of bulky items to external lash points.
- Compression straps – placement & gains:
- Wrap straps vertically and horizontally to compress lofty items (sleeping bag, jacket). Expect 10–25% reduction for synthetic/down bags; 20–40% for hybrid quilts and loose clothing when tightly cinched.
- Use 25–50 mm webbing with low-stretch buckles; tension until load is firm but not deforming gear. Two straps across main compartment and one across lid/brain covers most shapes.
- For long items (tent poles, skis) route straps through daisy chains or dedicated ski/ice-axe loops to keep them from canting and increasing drag.
- Stuff sacks – types and compression ratios:
- Compression stuff sacks with 2–4 straps: reduce volume 30–50% vs loose stuffing. Use appropriately sized sack so loft fills the cavity rather than leaving air gaps.
- Lightweight dry bags (1–2 mm TPU) double as water protection and can be rolled to fine-tune packed length; ideal for quilt/bag and jacket.
- Packing cubes: little/no compression but improve space efficiency by organizing and eliminating wasted pockets; combine cubes for modular compression.
- External carry points – what to move out and how much they save:
- Sleeping pad externally: saves ~5–10 L of internal space depending on pad thickness. Use side or bottom straps; keep pad parallel to torso to reduce snags.
- Tent poles/trekking poles: 1–3 L equivalent; use pole sleeve or lash points. If poles are telescoping, stow them inside the sack when possible to reduce wind drag.
- Wet items (rain jacket, soaked shell): stow in external pocket or top-of-bag lash; prevents moisture transfer and frees internal dry-sack capacity – estimate 0.5–2 L per item.
- Limit single external attachments to 4–8 kg total; assume 5 kg safe-load per major lash point unless manufacturer specifies higher rating.
- Load placement and balance:
- Keep the heaviest compressed items close to the hipbelt and near the centerline to maintain stable center of gravity when external items are attached.
- When using multiple external pieces, mirror-load left/right to avoid torque; if impossible, place heavier piece lower on the hip side.
- Compress vertically to shorten torso height required by the bag; a 10–15 cm reduction in stack height often downgrades required bag volume by one size category.
- Practical sequence for reducing carried volume:
- Weigh core items and note packed dimensions.
- Pack heavy, dense items near hips; stuff sacks for insulating layers and garments; apply compression straps.
- Move non-sensitive bulky items (pad, poles, tripod, camp shoes) to external lash points and re-measure overall height and girth.
- If internal volume still exceeds target, replace largest-volume item (sleeping system or shelter) with a lower-volume alternative or switch to a more compressible stuff sack.
- Quick reference numbers:
- Compression straps shrink 10–40% depending on item type.
- Compression stuff sacks reduce 20–50% vs uncompressed stuffing.
- External carry typically offloads 3–10 L without affecting core weight distribution when properly lashed.
- Assume 5 kg safe-load per primary lash point unless specified.
- Extra tip:
For urban transfers or family outings where a child seat is useful, consider a lightweight option such as best non toxic umbrella stroller to avoid over-stuffing the main bag.
