How to measure a radiator

What we’ll cover…

1. Key radiator measurements:
   • Height
   • Width
   • Pipe centres
   • Wall to pipe centres
2. Further considerations:
   • Wall distance
   • Wall to face measurements
   • BTU calculations
3. Typical radiator sizes and styles
4. Factors to influence radiator choice:
   • Existing heating system
   • Available space and layout
   • Room insulation properties
   • Intended installation location
5. Radiator measurement FAQs

Key tips for measuring a radiator

As our quest for customers to view home heating as home décor continues, we deemed it a good idea to fill you in on some of the key points to consider if you do decide to take the plunge and update radiators in your home.

And how to measure a radiator is certainly amongst a list of essentials you need to know before committing to renovate radiators in any room. In fact, ensuring you have noted the correct size of your existing radiator provides the prime foundation for a successful replacement job.

In this guide, we’ll zone in on the very best practices to correctly measure your radiators, ensuring nothing but the perfect fit when it comes to installing new radiators.

So, how do you accurately measure a radiator?

Let’s get started.

Measuring a radiator in 4 simple steps

We’ll get into more detail later, but you won’t go far wrong following these four basic steps to measure a standard radiator…

1. Measure the width
2. Measure the height
3. Measure the left pipe centre to the right pipe centre
4. Measure the wall to pipe centres

Calculating radiator width

Very simple. Just take your tape measure across the furthest point of your radiator from one side to the other to gain an accurate measurement of radiator width.

Calculating radiator height

Another easy one. Just use a tape measure from the foot of the radiator to its highest point to calculate radiator height.

Calculating pipe centres

The distance between the pair of pipe inlets on a radiator represents what we know as radiator pipe centres. To calculate their size, you should measure from the centre of one pipe to the centre of the other. Just use a tape measure from the middle of the left inlet to the middle of the right inlet to record an accurate pipe centre measurement.

Calculating wall to pipe centres

In calculating the wall to pipe centres, you are measuring the distance from the wall that your radiator’s pipe inlets sit as they enter the radiator valves. For an accurate reading, you should measure from the middle of your pipe inlet to the wall. The result will give an indication as to how far away from the wall your pipework is situated, and is extremely useful in helping you avoid invasive plumbing alterations when you decide to swap radiators.

Other key calculations for measuring a radiator

BTU calculations

When the time has arrived to change radiators, it’s imperative to know that your new designer radiator delivers a sufficient heat output for your chosen room. You can be sure that it does by calculating the BTU (British Thermal Units) requirements of the space.

You’ll need to measure the height, width and length of the room your new radiator is to be fitted in, and input these figures along with a few more details to our BTU Calculator.

Want to know more about BTUs? Check out our guide to BTU outputs, to learn what they are and why they’re important!

Wall distance

The gap between the wall and your radiator can be determined as the wall distance. It’s a useful measurement to record as it allows you to calculate how much space will remain behind your radiator once mounted.

Simply measure from the back of your radiator to the wall to assess the size of the gap accurately. And remember to account for extra room if you intend to fit a radiator cover.

Wall to face

For a wall to face measurement, you’re working out how far into your chosen room your new radiators will project. The distance is calculated from the furthest point on the face of your radiator to the wall.

Whilst this isn’t an especially crucial aspect of a like for like radiator replacement, it is useful if your new radiators or towel rails are being installed in a noticeably compact room with space at a premium.

Are there a standard radiator sizes?

For several years all domestic radiators in the UK tended to be very similar white metal boxes that came in five different sizes.

Thankfully, with the help of new technology, over the last decade or so, there is now no real limit to the size, shape and type of radiator you can buy.

Vertical, horizontal or column, it doesn’t really matter.

However, if your existing radiators haven’t been changed over the last few years, you will likely find them to be one of these five standard sizes –

• 400mm x 400mm
• 300mm x 100mm
• 400mm x 1200mm
• 600mm x 1200mm
• 600mm x 900mm

These are the most common UK radiator sizes, and the chances are your existing radiators fit into one of these 5 profiles.

Other considerations for measuring a radiator

Sizing your radiator need not be a daunting and time-consuming task.

Some additional factors when measuring for the size of radiator you need are –

• The current heating system you have
• The space you have available
• How hard it is to keep the room warm (insulation)
• Where you intend to locate it.

Consider all of the above when sizing your new radiator and you won’t go far wrong.

Using radiator measurements for radiator replacement

Once you’ve accurately measured your radiator and assessed your BTU requirements, you should be in a good position to put them to good use, and effectively replace your radiator without having to adjust any plumbing.

BestHeating offer all sorts of ultra-stylish modern designer radiators that will really enable you to transform your habitat, and realise the mantra of turning your home heating into home décor.

If you would like any further help or advice regarding how to measure a radiator, or have any heating queries at all, please don’t hesitate to get in touch with us. You can leave your thoughts in the comments section below, or contact us via Instagram, Facebook or Twitter.

Measuring your radiator – Frequently asked questions