Radiator Size Guide: How to Measure and Size Your Radiator

May 11, 2023 | News

Size a radiator

If you’re looking to upgrade or replace your radiator, knowing its size is crucial to ensure a smooth installation. In this guide, we’ll walk you through everything you need to know about how to size radiators, and correctly measure the dimensions of a central heating radiator – the kind that’s plugged directly into the boiler and heating supply.

How to Measure Your Radiator

To make sure your new radiator fits your plumbing and location specifications, you’ll need to take accurate measurements of your current radiator. Here are the steps you need to follow:

  1. Prepare the right tools: You’ll need a tape measure, pen and notepad, or your phone to record the measurements.
  2. Measure the radiator height: Measure from the lowest point of your radiator to the highest.
  3. Measure the radiator width: Measure from the furthest point on the left to the furthest point on the right of your radiator.
  4. Measure the pipe center to center distance: This is the distance between the two pipe inlets that feed into, and out of, your radiator.
  5. Measure the wall surface to the pipes’ centers: Begin at the wall and measure the short gap between the wall to the center of the pipes.
  6. Measure the depth of your current radiator: If it sticks out, you might consider replacing it with a slimline version.
  7. Measure the space behind your radiator: Measure the distance between the wall and the radiator.

All measurements should be taken in millimeters.

Book a boiler quote

Call our specialists on 020 8395 8616 or fill in our booking form.

What Size Radiator Do You Need?

Radiators come in various sizes and shapes to cater to different heating requirements and preferences. To calculate the ideal size of your radiator, you need to determine the British Thermal Units (BTU) required for your room. The BTU calculation takes into account the size and type of the room, such as a kitchen, bedroom, or common areas, and is usually expressed as a multiplication factor of the cubic feet of the room. Double glazing is also factored in by deducting 10% from the BTU calculation.

The table below provides a rough estimate of the correct BTU required for heating different rooms:

Room Multiplication Factor
Lounge and dining room Multiply cubic feet by 5
Bedrooms Multiply cubic feet by 4
Common areas – e.g. hallway or kitchen Multiply cubic feet by 3
For double glazing Deduct 10%

Radiator Tips

When buying a new radiator, it’s advisable to match its measurements precisely with the old one, unless you’re willing to make changes to your plumbing. You can research and compare different radiator models and deals online before visiting a showroom to see how the radiator sizing might appear in your home.

Proper maintenance of your radiators is essential for their longevity and energy efficiency. Regularly bleeding and balancing your radiators, and turning them off when not in use can help you save money on your heating bills. YourRepair, a boiler specialist, offers unlimited repairs and affordable plans starting from £8 per month to keep your boiler running and in top condition. If you need boiler cover, speak to one of our experts today.

In conclusion, measuring and sizing your radiator accurately is essential for a smooth installation and energy-efficient heating. With the right tools and measurements, you can find the ideal radiator to meet your heating needs and preferences.

Open chat
How can we help?