How to Measure for a New Door

Whether you are planning on replacing an external or internal door, it is best to make sure you know which size to look for first. In this handy guide we will walk you through taking measurements so you will get your door size right!

You might also want to have a look at our Door Size Guide in which we list all the standard door sizes in both metric and imperial measurements.

Measuring an existing door:

It is important that you take these measurements from the existing door frame - not the old door. All you need is a tape measure, a pen and paper.

Taking the measurements in millimetres will leave you with a more precise result.

1. Width: first you will want to measure the width across the top, middle and bottom of the frame opening. If they vary – write down the largest measurement as your required door width.
2. Height: to measure the height you will take three measurements: at the right-hand side, centrally and at the left-hand side. Again, write down the largest measurement for your door height. Important: measure the height within the door frame and take the floor covering into consideration.
3. Now that you have got your door measurements you can start looking for a new door.

Don't worry if your measurements vary a little as most doors can usually be trimmed down within certain tolerances. However, it is important to choose a door as close to your measurements as possible - especially when looking for fire doors as these often times can only be trimmed down by a few millimetres.

What if your measured size isn't a standard door size? A lot of doors are available as bespoke doors and can be manufactured to suit your needs. Please contact us if you're considering ordering a bespoke door. Please note: bespoke doors come on an extended lead time.

If you are unsure about which size to get, please contact us for advice.