Backpack Dimensions by Type, with Airline Size Limits
Outside measurements for every common kind of backpack, the laptop each one takes, and the airline, stadium and locker limits a backpack has to fit. For choosing capacity in liters and fitting a pack to your back, see the companion guide to backpack sizes.
A typical school or everyday backpack measures about 17–18 × 12–13 × 6–8 in (43–46 × 30–33 × 15–20 cm) and holds 20–30 liters. A backpack that travels as an airline personal item must stay near 17 × 13 × 8 in or smaller, while a carry-on travel backpack can be up to 22 × 14 × 9 in (56 × 36 × 23 cm), about 40–45 liters.
- School backpack
- 17–18 × 12–13 in
- Personal-item pack
- ≤ 17 × 13 × 8 in
- Carry-on pack
- 22 × 14 × 9 in
- Multi-day hiking
- 28–33 in tall
On this page
Backpack dimensions chart by type
Backpacks are sold by capacity in liters, but whether one fits under an airline seat, in a locker or on your back depends on its outside measurements. The ranges below are the overall height, width and depth of typical packs in each category when reasonably full.
| Type | Height × width × depth (in) | cm | Capacity | Largest laptop |
|---|---|---|---|---|
| Mini or fashion backpack | 10–12 × 8–10 × 4–5 | 25–30 × 20–25 × 10–13 | 5–10 L | None; tablet at most |
| Kids' school backpack | 12–16 × 9–12 × 4–6 | 30–41 × 23–30 × 10–15 | 8–18 L | Chromebook (11.6 in) in the larger sizes |
| School or everyday backpack | 17–18 × 12–13 × 6–8 | 43–46 × 30–33 × 15–20 | 20–30 L | 15.6 in |
| Laptop or commuter backpack | 17–19 × 11–13 × 5–8 | 43–48 × 28–33 × 13–20 | 15–30 L | 14 to 17.3 in, by model |
| Hiking daypack | 18–21 × 10–12 × 6–8 | 46–53 × 25–30 × 15–20 | 15–30 L | Usually no padded sleeve |
| Personal-item travel backpack | 16–17 × 11–13 × 6–8 | 41–43 × 28–33 × 15–20 | 18–28 L | 14–16 in |
| Carry-on travel backpack | 21–22 × 13–14 × 8–9 | 53–56 × 33–36 × 20–23 | 35–45 L | 16–17 in |
| Overnight hiking pack | 22–28 × 12–14 × 8–10 | 56–71 × 30–36 × 20–25 | 30–50 L | None |
| Multi-day backpacking pack | 28–33 × 13–15 × 10–12 | 71–84 × 33–38 × 25–30 | 50–80 L | None |
Two packs with the same liter rating can have different shapes. A tall, narrow 30-liter hiking pack and a short, boxy 30-liter travel pack hold the same amount, but only the travel pack fits an airline sizer. When dimensions matter, read the measurements, not the capacity. How to choose the capacity itself, and how to fit a pack to your torso, is covered in the backpack size and fit guide.
School backpack size
For middle school, high school and college, the common size is 17 to 18 in tall and 12 to 13 in wide. That is what it takes to carry a 1 to 1.5 in binder (about 11.5 × 10.5 in) flat, two or three textbooks and a laptop. Smaller packs force binders in at an angle, and taller ones sit below the hips on a shorter student.
- Binders and folders: a letter-size binder needs an interior of at least 12 × 11 in; an A4 binder needs about 12.5 × 11 in (32 × 28 cm).
- Lockers: school hallway lockers are commonly 12 in wide and 12 to 15 in deep, so a pack wider than 13 in or deeper than 10 in when full can be hard to fit beside a coat.
- Younger children need a pack sized to their torso, not their grade. The kids' backpack size chart by age gives heights and capacities from preschool up.
Laptop backpack size
The laptop sleeve sets the minimum height and width of a laptop backpack. A sleeve needs about 1 cm (0.4 in) of clearance beyond the laptop body, and the pack adds padding and fabric around it.
| Laptop size | Sleeve needed (inside) | Smallest practical backpack |
|---|---|---|
| 13–14 in | 13.2 × 9.3 in (33.5 × 23.5 cm) | 15–16 in tall, 15–20 L |
| 15.6–16 in | 14.6 × 9.8–10.2 in (37 × 25–26 cm) | 17 in tall, 20–25 L |
| 17.3 in | 16.1 × 10.6 in (41 × 27 cm) | 18–19 in tall, 28–35 L |
Gaming laptops are thicker and deeper than these figures, so match the sleeve's listed inside size to the laptop's spec sheet. Full compartment sizes for every laptop class are in the laptop bag size chart.
Backpack size limits for flights
On a plane a backpack travels either as a personal item, under the seat in front of you, or as a carry-on, in the overhead bin. Which role it can take depends on its size; whether your fare includes that role depends on the airline.
| Role | Airline | Limit (in) | Limit (cm) | Box volume |
|---|---|---|---|---|
| Personal item | United | 17 × 10 × 9 | 43 × 25 × 23 | 25 L |
| Personal item | JetBlue | 17 × 13 × 8 | 43 × 33 × 20 | 29 L |
| Personal item | Southwest | 16.25 × 13.5 × 8 | 41 × 34 × 20 | 29 L |
| Personal item | American, Frontier | 18 × 14 × 8 | 46 × 36 × 20 | 33 L |
| Free under-seat bag | Ryanair, Wizz Air | 15.7 × 11.8 × 7.9 | 40 × 30 × 20 | 24 L |
| Free under-seat bag | easyJet | 17.7 × 14.2 × 7.9 | 45 × 36 × 20 | 32 L |
| Carry-on | Most US airlines | 22 × 14 × 9 | 56 × 36 × 23 | 45 L |
| Carry-on | Many international airlines | 21.7 × 13.8–15.7 × 7.9–9 | 55 × 35–40 × 20–23 | 39–51 L |
Box volume is the upper bound. A backpack with a frame, padded straps and a rounded shape packs less than its box, so a pack advertised as 25 liters can still fit a 24-liter sizer, while a 30-liter pack that is packed tight usually will not. The carry-on rules by airline page lists weight limits and personal-item rules for more airlines.
Sizers measure everything that sticks out. Tuck hip-belt wings and loose compression straps away before you walk up to the gate, and empty the side water-bottle pockets, which can add 2 in (5 cm) to the width.
Hiking packs on planes
Backpacks over about 45 liters, and most packs with a rigid frame or a tall extension collar, exceed carry-on limits and must be checked. Put the pack inside a duffel or an airline-supplied bag so straps and buckles cannot catch on the baggage belt. Remove trekking poles and stove fuel: poles are generally not allowed in US carry-on bags, and fuel canisters are not allowed in either carry-on or checked baggage.
Bag size limits at stadiums, venues and gyms
- NFL and many college stadiums: clear plastic, vinyl or PVC bags up to 12 × 6 × 12 in (30 × 15 × 30 cm), or a one-gallon clear freezer bag, plus a small clutch about 4.5 × 6.5 in. Ordinary backpacks are not allowed.
- Concert venues and arenas: limits vary widely; small bags of about 12 × 12 × 6 in are common where any bag is allowed, and some venues allow only clear bags.
- Gym and office lockers: a standard 12 in wide locker takes a 20 to 25 liter backpack; a box locker of 12 × 12 in does not take a full school pack. Locker sizes are covered in the gym bag size guide.
Measuring a backpack
- Pack it as you will carry it. The depth of a soft pack can change by 3 in (8 cm) between empty and full.
- Measure height from the bottom to the top of the haul loop or lid with the pack standing up.
- Measure width across the widest point, including side pockets with bottles in them.
- Measure depth from the back panel to the front of the fullest pocket, including shoulder straps if they are padded and thick.
For photo gear, purpose-built packs with dividers are covered in camera bag sizes.
Frequently asked questions
What are good dimensions for a travel backpack in cm?
For a carry-on travel backpack, about 55 × 35 × 20 cm (21.7 × 13.8 × 7.9 in), roughly 38 liters. That fits the US 22 × 14 × 9 in limit and the cabin limits of Lufthansa, Air France, KLM, Emirates and Air Canada. For a backpack that must go under the seat on Ryanair or Wizz Air, the limit is 40 × 30 × 20 cm.
What is the average backpack size?
An average everyday or school backpack is about 18 in tall, 12 in wide and 6 to 8 in deep (46 × 30 × 15–20 cm), with a capacity of 20 to 30 liters. That size holds a 15.6-inch laptop, a few books and a water bottle.
Can a backpack be a personal item on a plane?
Yes, if it fits under the seat and within the airline's personal-item size, such as 17 × 10 × 9 in on United, 18 × 14 × 8 in on American or 40 × 30 × 20 cm on Ryanair. A 20 to 25 liter backpack that is not stuffed usually qualifies.
What size backpack fits a 17-inch laptop?
One with a laptop compartment of at least about 41 × 27 cm (16.1 × 10.6 in) inside, which means a backpack at least 18 to 19 in (46 to 48 cm) tall. Most 17-inch laptop backpacks are 30 to 35 liters.
Are backpacks allowed in stadiums?
Usually not. NFL stadiums and many other venues allow only clear bags no larger than 12 × 6 × 12 in, plus a small clutch about the size of a hand (4.5 × 6.5 in). Concert venues and theme parks set their own limits, so check the venue's bag policy.