How Big Is a 28-Inch Suitcase? Litres, Kilos and Who Actually Needs One

"28-inch" is the size most people mean when they say a big check-in suitcase. It is also a label that tells you very little. It does not say how many litres the case holds, how much the empty case weighs against your baggage allowance, or whether you will be able to lift it into a taxi boot once it is full. This post turns the label into numbers you can use, and works out who really needs a case this size and who is better off with something smaller.

We sell luggage, so we are not neutral. Every VOX figure below is copied from the published specifications on our own 28-inch check-in case pages, and where the pages say nothing we say so rather than guess.

The short answer

• The inch figure is a label, not a measurement you can rely on. Compare the published centimetres and litres, not the number on the swing tag.
• Capacity is the interior volume in litres. The two VOX 28-inch cases hold 79.83 L (magnesium aluminium) and 96.63 L (RPET, plus 16.66 L when expanded).
• The empty case uses up part of your allowance. The VOX cases weigh 5.75 kg and 5.15 kg before you pack a single shirt.
• A 28-inch case suits trips where you check a bag and carry a lot. For a weekend away or a carry-on-only trip it is more case than you need.

What "28-inch" actually tells you

The number is a size class. Luggage makers use it loosely for a case that is roughly that tall, and different brands put different external sizes behind the same label. So two cases that both say 28-inch can differ in their external size, and can differ in whether the figure includes the wheels and the handle.

The useful numbers are the ones a maker publishes in centimetres and litres. For the VOX cases they are these:

• VOX Magnesium Aluminium Voyage Box: external 70 × 45.5 × 27 cm, internal 69 × 44.5 × 26 cm, 79.83 L, 5.75 kg.
• VOX RPET Voyage Box: external 69 × 50 × 30 cm (35 cm deep expanded), internal 68 × 49 × 29 cm (34 cm expanded), 96.63 L plus 16.66 L expanded, 5.15 kg.

One thing we have not published, and will not guess: an overall size with the wheels and the handle included. The external figures above are the manufacturer's, and we have not added a total or a "fits the airline limit" claim to them. If an exact measurement matters for your airline, email hello@voxjourney.com and we will measure the actual case for you.

How many litres is that?

Litres are simply the inside of the case, worked out as length × width × depth in centimetres, divided by 1,000. You can check our figures yourself from the internal dimensions above:

• Magnesium aluminium: 69 × 44.5 × 26 cm is 79,833 cubic centimetres, which is 79.83 L.
• RPET: 68 × 49 × 29 cm is 96,628 cubic centimetres, which is 96.63 L. Opened to its 34 cm expanded depth, it becomes 113.29 L.

The RPET case is deeper and wider on the inside, which is why it holds more even though its external height is a centimetre shorter. That is worth knowing, because a case can look the same size in a photo and still hold noticeably more or less. If you are comparing any two cases, compare the litres, and be a little wary of a brand that gives only the inch figure.

Litres do not tell you how much you can pack, because clothes do not fill a case like water. What they give you is a fair way to compare two cases against each other. If you are deciding between our two, our comparison of the aluminium and RPET cases sets out the other differences.

The weight you lose before you pack

A big case is a big part of your allowance. The empty VOX magnesium aluminium case weighs 5.75 kg and the RPET case 5.15 kg. As an illustration only, since allowances differ by airline, fare and route: on a 20 kg allowance, the magnesium aluminium case leaves you 14.25 kg for everything you pack, and the RPET case leaves 14.85 kg. Change the figure to your own allowance and the sum is the same.

Two things follow from that:

1. Look at the allowance on your own ticket first. Some tickets give a total weight, others give a number of pieces with a limit each. We explain the difference in piece versus weight baggage allowance.
2. Weigh the packed case at home. A case that feels fine in the hallway can be over by the time the counter scales read it, and a full 28-inch case is the one most likely to surprise you.

Who a 28-inch case suits

• Long trips with a checked bag. If you are away for a couple of weeks or more and one case is doing the work, the extra volume is useful.
• Two people sharing one case. A couple who pack together can often get away with one big case instead of two smaller ones, provided the packed weight stays under the allowance.
• Trips with a return leg to fill. If you expect to come home with more than you left with, an expandable case gives you room in reserve. The RPET case expands by 5 cm for this; we look at whether that is worth having in is an expandable suitcase worth it.
• Anyone who dislikes having to leave things behind. If you tend to pack a bit of everything, a larger case removes the argument at the wardrobe.

Who should think twice

• Short trips and weekends. A big case invites you to fill it. If the trip is short, a smaller case keeps the weight down and is easier to move.
• Carry-on-only travellers. A 28-inch case is a check-in size. The VOX cases are sold as 28-inch check-in cases, and we have not published a cabin size. For cabin baggage the limits differ between airlines, as we explain in cabin baggage on budget and full-service airlines.
• People who lift cases a lot. Stairs, car boots and train steps add up. A fully packed 28-inch case is heavy, so think about how often you will lift it, not just how far you will wheel it.
• Anyone planning to take it on the MRT at rush hour. A big case is awkward in a crowded carriage and at fare gates. Read taking a big suitcase on the MRT to Changi before you commit to that route.

A five-minute test before you buy any case

1. Lay out what you would normally pack for your typical trip and photograph the pile. Then look at the litres of the case you are considering, not the inch figure.
2. Look up the empty weight and subtract it from your usual allowance. If what is left is less than you normally pack, you need a different size or a different packing plan.
3. Measure your boot, your wardrobe shelf or the space under your bed. A case that does not fit where you keep it will end up in the hallway.
4. Check the interior dimensions against anything awkward you carry regularly, such as a pair of boots or a rolled yoga mat.
5. Read the returns terms. If you can try the case at home and send it back unused, a wrong size is a small problem.

What VOX publishes, and what it does not

The published figures, nothing added:

• Both VOX cases are sold as 28-inch check-in cases.
• The VOX Magnesium Aluminium Voyage Box costs S$590 at the founders' price (S$690 retail).
• The VOX RPET Voyage Box costs S$290 at the founders' price (S$390 retail).
• Both have a TSA-approved combination lock and 360° multi-spinner wheels with cushion axles.
• The warranty is 5 years on the shell and wheels.
• Delivery in Singapore is free and takes 1–3 business days. You can return a case within 7 days of delivery in its original condition with the original box; email us first and we will confirm the details.

We have not published an overall size with the wheels and handle included, a cabin size, or an airline-by-airline guide to whether the case fits a particular limit. If you need one of those, ask us before you buy rather than assuming.

Which size should you choose?

• You check a bag and travel for weeks: a 28-inch case is a sensible size. Pick by litres, then by empty weight.
• You usually come home with more than you left with: look at a case that expands, and weigh it before the flight, because the extra room is also extra weight.
• Your trips are short or carry-on only: you probably do not need a 28-inch case at all.

Not sure if a 28-inch case suits the way you travel? Message us on WhatsApp and tell us how you travel, and we will tell you honestly whether a VOX case is the right size.