How big is my car's boot?

Cars provide mobility not only for ourselves, family and friends, but also everything else that comes along with them.

The ability to load essential items like our shopping and a stroller, or recreational items like a bicycle, have become a crucial part of the car buying equation.

The most common and fair method is called VDA, which is an acronym for the peak body representing the automotive industry in Germany (Verband der Automobilindustrie).

VDA aims to consider usable space by using a minimum block size that excludes small gaps which are not very beneficial.

Additionally for open cargo areas such as those found in SUVs, hatches and wagons, the volume is only listed to the top of the rearmost seats, which helps maintain rear-view visibility.

In some cases, VDA may be specifically listed “to roof”.

That’s all very straightforward, but unfortunately for buyers, calculating boot space is not that simple.

A second standard exists and is commonly used by global car-makers, referred to as SAE (Society of Automotive Engineers).

This calculation method considers the cargo area as sealed, and measures the total volume as if you were to fill it with water. Therefore, it generously includes non-practical gaps and crevices.

We’ve covered this in more detail in a previous story here, so let’s get on to the business of loading up your car in the real world.

Let’s say your new car comes with 450L VDA. Okay, got it, but what does that really mean? Here is a list of some common everyday items to help put some context to those numbers.

• Shopping bag – 20L
• Suitcase (carry-on) – 30L
• Suitcase (large) – 120L
• Golf clubs – 160L
• Adult bike – 250L
• Compact pram – 100L
• Standard pram – 200L
• Double pram – 280L

Considering the aforementioned 450L cargo space, numerically you should be able to fit a standard stroller, plus around 12 shopping bags.

However, we know in real-world circumstances the loading area and items are never perfect shapes that allow us to reach the full potential.

Similarly, the ability to stack items may be limited due to soft or fragile goods.

Adding around a 20 per cent margin, and considering stacking, realistically you may only fit between four and eight shopping bags.

As we’ve alluded to, the usability and practicality of the space is almost as important as the outright volume.

Lift-over height, or the distance you need to raise an item from the ground to the luggage area, will be best in something like a people-mover, and tend to be worse in true off-road vehicles that are higher to provide clearance for obstacles (known as departure angle).

Load lip, which is the distance from the rearmost portion of the vehicle to the cargo area, is another consideration. Traditional sedans tend to be the worst offenders with their deep rear bumpers.

The size of your boot opening is also a crucial factor. While most large sedans easily have enough volume to fit an adult bike, the shallow height of the opening usually means this is impossible or necessitates some disassembly.

Model variations according to standard equipment, powertrain and options selected may impact your vehicle’s storage capacity. A prime example of this is the Lexus UX.

The base-model Lexus UX 200 has 321L of boot space. Upgrading to the F-Sport means you lose the space-saver spare tyre and capacity increases to 371L. Going hybrid shrinks the petrol tank, but adds a battery and has marginally more storage than the petrol-only variant at 324L.

But the F-Sport hybrid is less than its petrol counterpart at 364L. Finally, the hybrid AWD versions measure at 334L.

On the other hand, the Audi Q3 SUV and its Sportback variation both have a listed boot space of 530L.

Despite the Sportback’s more aggressively raked rear glass, the VDA measurement does not include the area above the seatback. However, in real-world max loading situations, such as the airport run, the boxy SUV would win out.

Each individual or family's needs are different, further complicated due to the variability of measurement methods as well as access and shape of cargo areas.

As with many things, the best way to determine the most appropriate solution is a physical test. If boot space is important to you, make sure you load up next time you go car shopping.