A Guide to Bollard Height: Finding the Size You Need (Height & Diameter)

Bollards come in a range of sizes, but the most effective height of a bollard depends on its location and purpose. In general, bollards range from 500mm – 1200mm in height, so there are plenty of options to choose from. However, selecting the right height is important to ensure bollards and security posts are effective. In this article, we explore the factors that should be taken into account when selecting bollards based on height and diameter and take a closer look at how bollards of varying heights can meet your needs. 

parking post on grass

How Tall Should a Bollard Be?

Many people ask how tall bollards should be, but there is no minimum height requirement you must satisfy when installing bollards or security posts. Despite this, it’s important to consider four factors when you’re deciding what height bollards should be:

  • Function
  • Visibility
  • Safety
  • Aesthetic


Bollards and security posts are used for numerous reasons. You may be installing bollards to prevent unauthorised vehicular access, direct pedestrian traffic or protect against potential attacks on a building, for example.

The function of the bollard will impact the appropriate height and diameter. A bollard needn’t be particularly tall to prevent a vehicle from driving over it, for example. When you are using bollards to direct pedestrian traffic, however, taller bollards can be more effective as they prevent people from simply stepping over them.

Bollards and security posts are routinely available in a range of sizes, so you can choose the perfect height for a particular application. The RAM Telescopic Security Post is available at above-ground heights of 580mm, 670mm and 850mm, for example.


Although shorter bollards can be highly effective at preventing vehicular access, it’s important to remember that bollards should act as a visual deterrent, as well as a practical one. If shorter bollards aren’t clearly visible to drivers, there are likely to be many instances of vehicles inadvertently driving into them or getting their vehicles caught on them.

Due to this, you should consider how bollards can achieve maximum impact when you’re deciding what size bollards are best suited to your property. If bollards are going to be installed in areas with heavy traffic, low lighting or dense vegetation, taller bollards may be the best option as they will be more visible.

Similarly, selecting bollards with built-in features to increase visibility can be advantageous. For example, the Benito Stainless Steel Automatic Bollard is a fairly standard height at 600mm but the built-in LEDs and reflective band it has increases its visibility.


Another factor to consider when determining how tall bollards should be is how they will affect the safety of your site. When bollards are highly visible, they act as a visual deterrent, and they are less likely to pose a potential safety risk. By making sure you choose bollards that are tall enough to be seen clearly at all times, you can ensure that your security measures enhance the safety of your site, rather than minimising it.

Similarly, choosing bollards that are clearly visible in all weather conditions and in the dark or low lighting is another way to maximise on-site safety and increase the efficacy of your security protocols.


While function and safety are major factors in determining which bollards are best suited to specific applications, don’t overlook the importance of aesthetics. After all, the bollards you select will have a significant impact on the appearance of the area.

Although it may be tempting to choose the tallest bollards, this won’t necessarily maximise their functionality and they could detract from the aesthetic of the area. Instead, determine what size bollards are required to achieve optimal functionality, visibility and safety and then select bollards are security posts within these parameters to enhance the aesthetic of the space.

How Tall Are Bollards for Parking?

Bollards are routinely used in public and private car parks and homeowners frequently install security posts on residential driveways to protect their vehicles against theft or damage. Due to the number of collisions that occur in public car parks, installing security posts can be an effective way to create a safer environment.

Again, there are no specific requirements when it comes to the height of a parking bollard, but the surrounding area will have an impact on what height bollard you choose. Our Stainless Steel Plain Fixed Bollard can be ideal for parking areas and offers 1000mm above-ground height, for example.

How Tall Is a Bollard (in Total)?

When you’re selecting which bollards to install, be sure to check the above-ground and total height measurements. During the installation process, the bollard will be inserted into the ground and, therefore, some of its total height won’t be visible above ground.

Fortunately, most manufacturers display clear ‘total’ and ‘above ground’ measurements, so it’s easy to determine how tall the bollard will appear to be once it has been securely installed in the ground. For example, the Stainless Steel Plain Fixed Bollard is 1400mm tall in total, with 1000mm visible above-ground and 400mm set below the ground during installation.

Remember – a deeper install can enhance the strength and efficacy of the bollard, so choosing security posts with a substantial ‘below ground’ element can be a viable way to increase the effectiveness and stopping power of the bollards.

How Wide Should a Bollard Be?

Again, there are no set rules when it comes to how wide a bollard should be, so you will need to consider function, visibility, safety and aesthetics when selecting a bollard based on diameter. If the area is prone to heavy foot traffic, for example, thinner bollards may be best suited to the space.

Many people assume that the wider a bollard is, the more stopping power it has, but this isn’t always the case. For example, the Heavy Duty RB 101 Galvanised Steel Bollard is just 168mm in diameter yet is capable of protecting against intentional or accidental vehicular impacts.

Selecting the Right Bollards for Every Application

As you can see, there are a variety of factors to consider when it comes to selecting bollards and security posts. From how tall is a bollard to what material is a security post made from, you’ll need to assess the desired function and application to determine which bollards will deliver the best performance.

Of course, our expert team is always on hand to provide help and assistance. If you want to find out more about our range of bollards and security posts or you’d like guidance in selecting the right bollards for an upcoming project, contact Bison Security Posts on 01708 956833 or send us a message here.