Are you facing renovation of your flat? You need to change internal doors, but you have no idea how to get down to it? It doesn’t matter if you have a flat in a new constructed building or an old one, replacement of a door leaf is really not that difficult. Following a few simple rules will save you time and money. In a moment you will find out how to measure the size of internal doors.

The ABC of internal door replacement

Regardless of which internal doors are to be replaced, it is crucial to accurately measure the door opening which we will choose appropriate door frames and doors for. Before proceeding to measurements, it is worth knowing what door opening dimensions and door leaf dimensions really mean. When talking about measuring the door opening, we mean measuring the width and height of the opening, without the installed door frame, where we will install a new door frame and door. A door leaf dimensions is nothing more than a standard door dimensions, common for all door manufacturers.

Step by step measurement

The first step in measuring an interior door is to measure the door opening, which is the width and height of the opening in the wall. Using a metal building tape measure, measure the height from the top edge to the floor. It is best to measure in several places and record the lowest measurement. Next, measure the width of the opening in which we will place the door with the frame. By width we mean the distance from the left to the right edge of the opening in the wall. In this case, also measure in several places, preferably at the top, in the middle and at the bottom. Record the lowest result. The next important step is to measure the thickness of the wall. This is important because doors are sold with frames of different widths and it is important that they are narrower than the thickness of the wall. Take measurements in several places – at the left and right side edges as well as at the top. If we decide on a fixed door frame, we choose the highest result. In case of adjustable door frame, we choose the lowest result.

When choosing a door, we have to decide whether it should be right-handed door or left-handed door. The difference between them lies in the location of the hinges and the direction of opening the leaf. In the case of right-handed doors, the hinge will be located on the right side and the leaf will open to the right. In the case of left-handed ones – exactly the opposite.

The last issue is to choose a door with the right width that fits the measurements we have made. When it comes to replacing the door without the frame, the first thing to consider is whether the door is in a newly constructed building or an old one. The the former case, the door will be made according to current dimensions, which are standardized by Polish construction law. Measurements for such doors should start with the width, which can be measured from the outside. A size 60 door will be 64.4 cm wide, while a size 70 will be 74.4 cm wide – each subsequent size will be an additional 10 cm wide. Next, measure the height, which is nominally 203.5 cm. If the leaf is shorter, it may have been shortened, and we have to take into consideration that the new leaf will also need to be shortened. Other dimensions are always the same (the height on which the handle and hinges are installed). When choosing a door, it is also worth paying attention to the number of hinges. If the door frame has only two, we should look for doors with only two hinges. If the doors are of an old type, there is little chance to hang a new leaf on the old door frame, due to different spacing and diameter of hinges, height on which handle is installed, strike plate, and different shape of door and frame rebates. In this case, we must either replace the frame with a new one, or use the CMOK overlay frame, which does not require removal of the old frame. 

If we have taken all the measurements as indicated above, we can proceed to ordering the door leaf. In case of questions and difficulties, it is best to contact the door manufacturer and ask for details.