Suitcase capacity - how to calculate it and when it’s important to know?

When choosing a suitcase, we usually consider primarily its dimensions and appearance. However, it is worth knowing its volume. This way, we can better estimate how much luggage will fit inside. Contrary to appearances, it is very easy to calculate. You only need to know the suitcase’s dimensions.

Why are dimensions and capacity important at all?

The dimensions of a suitcase are not only practically important, related to the size of the luggage we plan to take. We can decide for ourselves how large a suitcase we will take by car, train, or plane, but it is important to remember that this involves various costs, and not only that. For a car, the limitation is the size of the trunk. On a train, it is the allowed maximum luggage dimensions, and on a plane, the matter is more complex. There is carry-on luggage – small and larger – and checked luggage. Carry-on luggage can be free of charge as long as it fits within the size limits of the airline. Such luggage is taken on board the plane. If you want to travel on a budget, it is important to know not only the allowed dimensions but also how much you can fit inside. This makes it much easier to estimate whether you can travel with only that luggage.

What is checked luggage and what is carry-on luggage?

As mentioned, carry-on luggage is a small travel bag, backpack, or handbag. It can also be expanded to include a cabin suitcase (also with specific dimensions), which is additionally charged. The restrictions here concern not only dimensions but also the weight of the carry-on luggage. The same applies to larger suitcases. For checked luggage, we have the greatest possibilities because it is a large suitcase placed in the luggage hold. Such a suitcase can easily be packed for long and distant vacations. Its capacity is considerable, and the maximum weight is at least twice that of a cabin suitcase.

Carry-on luggage dimensions in low-cost airlines

When traveling by plane, we can have carry-on luggage in two options. The first is free carry-on luggage. You do not have to pay extra for it with the ticket price. It can be a woman’s or man’s handbag, but also a laptop bag. But that’s not all. Backpacks and travel bags also fit within the size limits. Depending on the airline, their dimensions vary slightly. For Wizzair, carry-on luggage cannot exceed 40 cm x 30 cm x 20 cm. Ryanair allows luggage with dimensions 40 cm x 25 cm x 20 cm. The weight of such carry-on luggage cannot exceed 10 kg.
There is also a second option for carry-on luggage. For a fee, we can additionally have a cabin suitcase on board the plane. For Wizzair, its dimensions cannot be larger than 55 cm x 40 cm x 23 cm. Ryanair allows bringing a suitcase with dimensions 55 cm x 40 cm x 20 cm. It is worth remembering that the size of carry-on luggage affects the ticket price.

Checked luggage dimensions

Checked luggage refers to suitcases that are handed over to the luggage hold. These are large suitcases that hold a lot, but when traveling with scheduled airlines, we also have to consider restrictions. What kind? For checked luggage with Wizzair, the dimensions are 149 cm x 119 cm x 171 cm. For Ryanair, the allowed dimensions are 81 cm x 119 cm x 119 cm. Weight also matters. With Ryanair, you can take luggage up to 20 kg. Wizzair allows transporting checked luggage up to 32 kg. It is worth analyzing all this data carefully when purchasing a plane ticket to determine your needs and balance the budget related to the necessity of paying extra for such luggage. For shorter trips, it is better to pack optimally into carry-on luggage. A well-packed suitcase can be taken even for several days of travel without the need to buy often expensive luggage tickets. When choosing large suitcases and considering the weight limit, it is worth noting that suitcases should be made of solid materials to support such weight and also to withstand sometimes improper handling by airport staff. Checked luggage is always stored in the luggage hold during the flight.

Dimensions, weight, but how much can we actually fit in a suitcase? How to estimate?

Once we know what dimensions and weight of a suitcase are allowed on a plane, it’s time to estimate how much luggage that actually is. It is often hard to imagine how many things we can fit in a cabin suitcase, medium or large suitcase, as well as in a bag or backpack. This is where information about capacity comes in handy. How to calculate the capacity of a bag or suitcase will be explained shortly. It is worth getting familiar with the sizes to have an idea. If we travel for:

• 3-4 days - a backpack, bag, or cabin suitcase with a capacity of about 30-40 liters will be enough;

• 4-7 days - a medium suitcase with a capacity of 50-80 liters will be ideal;

• more than 7 days - a large suitcase with a capacity of about 100 liters is necessary.

Such estimates make it easier to determine what kind of luggage we need and whether the suitcase we have or plan to buy will be suitable. However, we do not always have data on the suitcase’s capacity. So how to calculate the capacity of a bag, suitcase, or other types of luggage to know how many things will fit inside?

How to calculate the capacity of a suitcase?

If we want to know the capacity of a suitcase, bag, or backpack, we need to know its internal dimensions. Usually, this requires measuring them. What data do we need? Width, height, and depth of the luggage measured. Once we know these dimensions, it’s time to apply them to a simple formula:

width of the suitcase in meters x depth in meters x length in meters x 1000 = capacity in liters

When converting centimeters to meters, remember that 10 cm is 0.1 m. So if the luggage dimension is 76 cm, enter 0.76 m in the formula.

This simple formula allows quick calculation of capacity. It is important to base it on internal dimensions, not total suitcase dimensions, as using incorrect values will give a false result.

Sometimes you don’t have to calculate anything – just check it!

If you are buying your suitcase for travel, there is no problem estimating capacity. The best brands provide this information on their product cards. An example is Wings, where for every suitcase, backpack, or bag, you will find information about capacity. This makes it easier to understand what kind of luggage you are buying. It is very convenient.

Do airlines specify luggage capacity limits?

Currently, airlines base their luggage size restrictions on dimensions. Capacity does not matter as much since it results from dimensions. Why are dimensions more important to airlines than capacity? Carriers have their measuring devices at the airport. The luggage should fit into them. If they only specified capacity, it would be difficult to verify quickly at the airport.

The possibility of taking many types of luggage and the different sizes of suitcases, bags, and backpacks sometimes make it confusing how large luggage we are actually buying or need. Determining its capacity greatly simplifies the matter.