How to measure for doors

Measuring for a new door can seem like a daunting task but with the help of this handy guide, you’ll be sure to measure correctly and save yourself the hassle of an ill-fitting door. First things first, what you need to effectively measure for your new door is a tape measure, although the most obvious piece of equipment you’d be surprised on how many people try and measure with a 30cm ruler. If you know how to use a tape measure, you can measure a door frame accurately. A tricky part can be knowing where to take the measurements: do you measure the door itself, the door frame or the entire opening?

It is important to remember if you are measuring for a replacement door to never measure the existing door. Always base your measurements on the door frame, this is because the door frame could have changed size through environmental changes, been unevenly installed or created in an old home. Although the height and width of the existing door should not be measured it can be useful to measure the thickness of the door you need, a standard door will have a thickness of 35mm.

To measure for an interior door first start with the width using a tape measure; measure across the door frame. Take three measurements – one from the top of the door frame, one from the middle and one from the bottom. Always take the widest width as your measurement as this determines the width of the door you need. Next is the door height – measure the inside of each vertical side of the frame; take three measurements one on the left side, one in the middle and one from the right-hand side. The longest length determines the height of the door you will require. It is important to remember to make allowance for any floor coverings. 

For an external door, you need to measure the width the same as an internal door again in three places for accuracy. The height is a little trickier – you need to ensure your measurement is taken from where your new frame or step will, in the end, sit on. If your door has a sill then this needs to be included in your height measurement. Again take three measurements to be accurate. A diagonal measurement is also beneficial as it can ensure that the opening for your door is square. 

Once you have all of your measurements it’s time to look for the door, remember you are able to plane the door to reduce the size slightly. Here at Moda Doors, we have a great selection of door sizes in both our internal and external door ranges. If your size of the door isn’t in our standard sizes, we do offer a bespoke door service.