Luggage & Bag Volume Calculator in Litres
Calculate bag or suitcase volume in litres (liters) from cm or inches. Estimate exterior box volume, not usable packing capacity or airline approval.
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Practical context, assumptions, examples, and next steps for using the result well.Explore it: outside size is not packing space
Predict first: would two bags with identical outside dimensions always hold the same amount? No. The enclosing box measures overall size, while wheels, handles, curved corners and construction affect usable space. Try this separate worked example; it does not change your calculator inputs.
Before you try: Two bags have the same outside dimensions. Must they have the same packing capacity?
Outside · measure the whole bag
The dashed box includes empty space around the handle, wheels and rounded corners. No packing-capacity percentage is assumed.
Dimensions describe the entire bag, including handles and wheels. The inch values are the same measurements, converted.
55 × 40 × 20 cm = 44.0 L of exterior box volume.
Each dimension multiplies the others. Increasing depth from 20 to 30 cm adds 50% to the box volume when height and width stay fixed.
Think it through: If only the depth doubles, does the box volume double?
Yes. With height and width fixed, volume is proportional to depth. But that still describes the outside box, not the litres you can pack. Handles, wheels, curved corners, lining and the case structure occupy or exclude space.
At 55 × 40 × 20 cm, the outside box is 44 L. Increasing only the depth to 30 cm makes it 66 L. Neither figure establishes packing capacity or airline acceptance; compare each outside dimension with your booking's rules.
Bag and suitcase volume in litres
Use this luggage and bag volume calculator to turn three outside measurements into litres and cubic inches. It works for a suitcase, backpack, duffel, or travel bag. Litres and liters mean the same unit: the spelling changes, not the calculation. The result estimates the volume of a rectangular box enclosing your bag, not the space available inside it for packing.
For measurements in centimetres, the formula is length × width × depth ÷ 1,000 = litres. A suitcase measuring 55 × 40 × 20 cm gives 44,000 cubic centimetres, or 44 litres. If you measure in inches, select Imperial before entering the values. The calculator converts the measurements and shows the same volume in both litres and cubic inches.
Exterior box volume gives you a consistent way to compare the overall size of bags, provided you measure them the same way. It cannot tell you how many clothes fit, whether a bag fits under a particular seat, or whether your ticket includes it. There is no fixed reduction that turns this result into usable packing capacity. Airline acceptance depends on dimensions and booking conditions, not a litre category.
How to measure a packed bag
Set the closed bag on a flat surface and measure along three perpendicular directions. A suitcase's height can be entered as its length; the names do not change the multiplication. Keep all three measurements in the selected unit. Do not enter one dimension in inches and the others in centimetres.
- Length or height: measure the full end-to-end extent of the bag.
- Width: measure across its widest side-to-side point.
- Depth: measure front to back, including filled outer pockets.
- Linear dimensions: add the three measurements when a policy asks for their combined total.
Measure a soft bag after packing because fabric and pockets can bulge. If you will use an expansion zip, measure with that zip open and the case packed as it will travel. Measuring only the empty shell can miss the shape that must fit a baggage sizer. A straight edge beside a wheel or handle can help you find an outermost point.
For the easyJet comparison shown here, include handles and wheels: its official policy explicitly includes them. For another carrier, follow that carrier's instructions rather than assuming every airline uses identical wording. Avoid rounding a measurement down to make it fit a limit. The displayed volume is rounded for readability, but the dimension comparison uses the entered measurements.
Free underseat bags versus larger cabin bags
“Cabin bag” does not necessarily mean a bag included free with every ticket. A small underseat allowance and a larger overhead allowance can have different dimensions and purchase conditions. Check which allowance is listed on your booking before deciding which comparison matters. A bag within an overhead size limit may still be too large for the free underseat allowance.
The example below comes from the official easyJet cabin bag policy, checked 31 October 2026. These are easyJet allowances, not universal airline standards.
| Bag | Maximum outside size | Allowance |
|---|---|---|
| Small underseat | 45 × 36 × 20 cm | One free per person; kept under the seat in front |
| Large cabin | 56 × 45 × 25 cm | Purchase separately or use eligible fare / membership benefits |
Both size limits include handles and wheels. Each bag can weigh up to 15 kg, and you must be able to lift and carry it yourself. easyJet Plus and Inclusive Plus benefits have specific conditions. Large bags not booked in advance under easyJet Plus, and large bags under Inclusive Plus fares, are subject to cabin space and may travel in the hold. Review the linked policy and your booking before departure.
“Within dimensions” in this calculator means only that the three sides fit the listed limits when oriented appropriately. It does not check weight, entitlement, available space, bag count, contents, or changes to policy. For other airlines and checked baggage, compare your measurements with the official rules for your itinerary.
Converting bag dimensions to litres
A litre is 1,000 cubic centimetres. Multiplying three lengths in centimetres produces cubic centimetres, so dividing by 1,000 gives litres. Multiplying three lengths in inches produces cubic inches instead. One cubic inch is 0.016387064 litres, and one litre is approximately 61.024 cubic inches. Do not use a length conversion alone to convert a volume: the factor applies in all three directions.
- 55 × 40 × 20 cm: 44,000 cm³ ÷ 1,000 = 44 L.
- 45 × 36 × 20 cm: 32,400 cm³ ÷ 1,000 = 32.4 L.
- 56 × 45 × 25 cm: 63,000 cm³ ÷ 1,000 = 63 L.
The last two figures are exterior boxes derived from the cited easyJet dimensions. They are not advertised bag capacities or allowances expressed in litres. A bag with a volume below 32.4 L can still exceed one of the small-bag dimensions. For example, 60 × 20 × 20 cm gives only 24 L, but its 60 cm side exceeds both easyJet examples above.
When comparing a manufacturer's capacity with this result, first check what the manufacturer measured. An internal capacity, an expanded capacity, and an outside box volume are different quantities even when they all use litres. A conversion changes the unit; it does not remove those measurement differences.
Choosing a bag without relying on a litre label
Begin with the restrictions you actually need to meet. If you want to travel with only an included underseat bag, look at that allowance rather than the largest cabin bag the airline sells. If your itinerary involves several carriers, check every flight. A product sold as “carry-on luggage” is not a promise that it meets all carriers' rules.
Next, compare bags using consistent outside measurements and inspect their internal layouts. A wide opening, accessible compartments, or a flat packing base may matter more than a small difference in calculated exterior volume. Consider whether your largest item fits through the opening and sits comfortably inside the bag, not just whether its own volume is smaller.
Check the empty weight and how the bag handles when loaded. Wheels, grab handles, shoulder straps, and the distance you will carry it affect the practical choice. A larger case can be useful for bulky equipment, but a smaller bag may be easier to lift onto a train or carry upstairs. Choose around your actual packing list, transport, and allowance rather than a universal “best size.”
Exterior volume versus usable packing capacity
A rectangular box around a suitcase includes spaces that you cannot pack. Rounded corners leave gaps inside that box, while lining, dividers, handle channels, and wheel housings occupy parts of the case. The effect depends on the design. This calculator deliberately does not subtract a standard percentage or label its result as internal capacity.
Soft-sided bags introduce another uncertainty: the packed shape changes with the contents. A loose duffel can fill out, while a backpack may taper towards the top. Multiplying their maximum outside dimensions still gives a useful enclosing box, but it does not model every curve or compartment. Applying the same reduction to a tapered backpack and a rigid suitcase would suggest precision that is not there.
For a better idea of usable space, read the manufacturer's capacity description and measurement method, then test-pack if possible. Check whether the quoted capacity includes expansion or external pockets. Packing cubes can help organize contents; compression may reduce the space occupied by some clothing. Neither changes the external size limit or guarantees a fixed improvement for every packing list.
Planning capacity for your trip
Trip length alone cannot determine the required litres. A few days with winter boots and equipment can need more space than a longer warm-weather trip with laundry access. Start with essential clothing, footwear, toiletries, medication, and equipment. Separate items that must remain accessible from those that can be packed at the bottom.
Test-pack the bag before travel, close it without forcing the zip, and measure it in that state. If the pockets bulge past the allowance, reduce or rearrange the contents rather than relying on the empty-bag dimensions. Weigh it separately. An apparently spacious bag can reach a weight limit before you have used all its available space.
Think about the return journey too. Gifts, purchases, or clothing packed less neatly may need additional room. Leave space if your plans require it, but do not treat an expansion zip as automatic permission to carry a larger bag. Recheck the packed dimensions and your return-flight allowance after adding items.
Using volume, weight, and linear dimensions together
Keep three separate questions in mind: how large is the outside box, how heavy is the packed bag, and which measurements does your airline restrict? This calculator answers the first and provides the length-plus-width-plus-depth total. It cannot infer weight from volume because clothing, books, shoes, and electronics have different densities.
Linear dimensions use addition rather than multiplication. For the 55 × 40 × 20 cm example, the sum is 115 cm while the box volume is 44 L. Use the sum only when your policy specifies a combined limit. Passing a combined limit does not establish that each side meets a separate cabin-bag limit, and there is no universal checked-bag threshold built into this calculator.
For multiple bags, calculate and check each separately. Adding their volumes may help compare your overall luggage, but it does not combine individual size or weight allowances. Whether you can pool allowances depends on the booking rules. Before departure, confirm the permitted bag count, packed dimensions, packed weight, and purchase or fare conditions directly with the airline.
Frequently Asked Questions
How do I calculate bag volume in litres?
Multiply length × width × depth in centimetres, then divide by 1,000. A bag measuring 55 × 40 × 20 cm has an exterior box volume of 44 litres. For measurements in inches, multiply the three dimensions by 0.016387064 to get litres. Outside measurements describe the box enclosing the bag, not its usable packing capacity.
Is a bag liter calculator different from a litre calculator?
No. Liter and litre are two spellings of the same volume unit, abbreviated L. This calculator works for bags, suitcases, backpacks, and other luggage using three outside measurements. Choose centimetres or inches before entering dimensions; the result includes both litres and cubic inches.
How do I measure my suitcase for this calculator?
Measure the packed suitcase at its widest points along three perpendicular directions: height or length, width, and depth. Include protruding parts when finding the outside box dimensions. For easyJet's published cabin limits, handles and wheels are explicitly included. Check another airline's own measurement instructions before using the figures for travel.
Does a 44-litre bag qualify as airline carry-on luggage?
Not automatically. Two bags can have the same volume but different outside dimensions. Cabin acceptance depends on the airline's individual dimension limits, weight rules, bag count, and what your booking includes. The calculator compares dimensions with the cited easyJet limits; it does not confirm airline approval or a free allowance.
What is the difference between easyJet's free and large cabin bags?
According to easyJet's official cabin bag policy, checked 31 October 2026, everyone can bring one free small underseat bag up to 45 × 36 × 20 cm. A large cabin bag up to 56 × 45 × 25 cm requires purchase or eligible fare or membership benefits. Both limits include handles and wheels. Each bag can weigh up to 15 kg and must be manageable without assistance. Some large-bag benefits are subject to cabin space; check your booking and the linked official policy.
Can I convert exterior suitcase volume to usable packing capacity?
There is no reliable fixed percentage. Rounded corners, lining, dividers, handle channels, and wheel housings affect the space inside each design differently. Use the manufacturer's stated internal capacity and measurement method, or test-pack the bag. This calculator does not apply a packing-space reduction or estimate how many clothes will fit.
How much luggage volume do I need for a week?
Start with your packing list rather than a universal litre allowance. Climate, footwear, equipment, laundry access, and personal needs change the space required. Test-pack your essentials, then measure and weigh the closed bag. Packing cubes can organize items, but they do not increase the bag's physical dimensions or guarantee a particular space saving.
How are linear dimensions different from suitcase volume?
Linear dimensions add length, width, and depth; volume multiplies them. A 55 × 40 × 20 cm bag totals 115 linear centimetres and 44 litres of exterior box volume. If your checked-bag policy gives a maximum linear total, compare the sum with that specific rule. There is no single checked-bag limit that applies to every airline.