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How To Measure A Radiator

When do I need to measure a radiator?

If you’re looking to replace a radiator in your home, either due to a malfunction of the unit or due to a change in aesthetics, you’ll need to make sure that the new model adheres to a range of measurements you’ll learn to take here.

Outside of the above, we generally don’t recommend changing your radiators or heating systems, as this can cause unnecessary disruptions to the system.

Tools required to measure a radiator

You don’t need a huge range of tools when simply measuring a radiator. You’ll need the following:

  • Tape measure
  • Pen or pencil
  • Note-taking device (paper, notepad, smartphone app)

Step-by-step guide to measuring a radiator

When measuring a radiator, there are five key measurements that need to be taken when considering a replacement.

  • The height of the radiator
  • The width of the radiator
  • The distance between the pipe centres
  • The distance from the wall to the pipe centres
  • The number of panels and convectors your radiator has

Generally, these measurements will allow you to make the decision about replacing your radiator.

To measure the height, you want to use a tape measure and note the length from the bottom of the radiator to the top of the radiator. It’s very important to measure the radiator itself, ignoring the gap from the bottom of the radiator to the floor.

This measurement is simply taken from the far left to the far right of the radiator itself. If you cannot reach from one side of the radiator to the other, we recommend getting a second person to help you with this measurement.

This measurement runs from the centre point of each pipe inlet, providing you with an important measurement when searching for a replacement radiator. Although mounting brackets can be moved if two radiators don’t match size-wise, it’s important that they both have the same pipe centre measurement, as the task of moving your pipes is incredibly difficult and time-consuming.

This is another important measurement when considering a replacement radiator. If two radiator inlet points aren’t the same distance from the wall, you’ll once again be in a position where pipework needs to be moved.

To measure this, simply use the same centre point of the pipe from your previous measurement and note the distance from here to the near wall. We recommend doing this for both pipes, though the measurements should be the same.

Most radiator manufacturers will have the exact measurements of their radiators available on their website which can help when choosing a replacement.

This very important to get this right otherwise you could end up with a radiator which cannot heat the room adequately.

A radiator can have a different variation of “Panel” and “Convector”. The Panel is the radiator itself and the Convector is the row of fins fixed to the back of the panel. Older radiators might not have a convector at all.

Below are examples of the most common types of radiator. It is important to choose a radiator which has the same number of panels and convectors if you are doing a direct replacement.


Although a relatively simple task, it’s important to do conduct diligence when considering a radiator replacement. Getting two similarly-sized radiators can go a long way in making an otherwise laborious and tricky task much simpler and quick.