How to Measure Doors: 5 Simple Steps

GreenMatch
Doors
How to Measure Doors

Last updated: 29 August 2023

How to Measure Doors for Replacement: 5 Simple Steps

Measuring your existing door ahead of fitting a replacement is incredibly important as you don’t want to end up with a door that doesn’t fit. Follow the steps in this article to make sure that you get those measurements spot on.

If you’re looking for the best professionals to install your new doors, choose GreenMatch. We can connect you with up to 4 new door installers within 48 hours. This saves you all the time and effort from finding suitable options independently. Instead, all you have to do is fill in our quick and easy form, then we’ll do the rest. With up to 4 tailored quotes, you can easily compare and choose the best deal.

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Imperial or Metric?

Let’s get the big question out of the way early: should you take imperial (metres) or metric (inches) measurements? Well, to get the most accurate measurements, we highly recommend measuring in millimetres rather than inches. This way, your installer will be able to make sure that your replacement door is going to fit perfectly.

How to Measure Door Size

All you need to measure the door is a tape measure, once you’ve got that follow these 5 simple steps:

Measure the width: Run the tape measure across the width of the door from left to right; only measuring the door itself and not the surrounding frame or any other parts. If you have a frame but no door, measure from the inside of the frame, where the door would be.
Measure the height: Again, if there isn’t currently a door in the frame, measure from the inside of the top frame down to the ground.
Take multiple measurements: Over time, a door might warp or wear down meaning that it’s no longer an exact rectangle. It’s a good idea to measure the height and width in a few different locations, especially in the case of taking wooden door measurements:

Width: Towards the top, in the centre and towards the bottom.

Height: To the left, in the centre and the right-hand side.

Once you’ve done that, you’ll have 6 measurements overall. Take the largest measurement for the height and the width and use them to let the installer know the size of door you need.
Measure the thicknessIt’s not enough to measure the height and width of the door, you’ll also need to find out how thick the door measures. You should also get a measurement of the door frame (jamb) too, which is where the door sits within the frame when closed.
Measure the door frameMeasuring the frame of a door is similar to measuring the door itself. To measure the height, run the tape measure up the inside of the door frame from top to bottom and then take 3 measurements of the width: across the top, middle and bottom sections.

Note that if you’re unsure of any measurements that you take, it’s always better to round down than up to ensure that the new door will fit.

Don’t Forget to Double Check the Measurements

It’s always a good idea to take the measurement a couple of times so that you can be confident that you’ve got the most accurate measurement.

Not Sure? Ask a professional

Should you not feel comfortable taking the measurements or have any doubts whatsoever, then don’t hesitate to contact a professional who will be able to take an accurate measurement of your door.

Standard Door Measurements UK

The average height of a door is 1981mm (78 inches), while the width tends to be around 762mm (30 inches). Thickness is commonly measured at 40mm. In Scotland, doors tend to be slightly taller (2040mm) and narrower (726mm) but have the same thickness.

For a frame that doesn’t sit within the ‘standard’ size, then you’re likely to require a bespoke door, made specifically for your installation.

Time to Get Installation Quotes

Now that you know how to take measurements for a replacement door, it’s time to get installation quotes from trusted professionals.

By completing one of our simple online forms, you’ll get free installation quotes from up to 4 qualified installers in your local area. You’ll then be able to compare the quotes and hire the installer that provides the most favourable quote.