Velux Window Sizes Guide

With almost 80 years of experience in the production of premium roof windows, VELUX blends stunning designs with cutting-edge technology and leading manufacturing processes. No matter where you install them, Velux windows give the place a special flair. And it isn’t just aesthetics either, they increase ventilation and allow natural lighting in.

That’s why it is all the more important to find and install Velux windows of the right size. Sadly, though, finding the ideal window size for your project can be challenging. This is particularly true if this is your first time looking for a roof window. Keep in mind that the aesthetics and comfort of your home greatly depend on the size of the windows you choose. And this article, we’ll guide you through it. 

How are Velux Windows Measured? 

Understanding how VELUX windows are measured is crucial when choosing one. Most of the time, the measurements presented in regards to Velux roof windows refer to the external frame dimension rather than the pane area. This should roughly represent the size of the hole you’ll need in your roof deck (though flashings and accessories might impact this). 

How are Velux Window Sizes Codified? 

The code corresponding to the size of the Velux window is shown in the table below. These codes are unified across all retailers that offer Velux windows, so you won’t have trouble finding a window with the right size.

But keep in mind that the size, frame design, glazing choice, and opening type may all affect the width and height shown in this Velux window size chart. 

Code Width Height
VELUX BK04 47cm 98cm
VELUX CK01 55cm 70cm
VELUX CK02 55cm 78cm
VELUX CK04 55cm 98cm
VELUX CK06 55cm 118cm
VELUX FK04 66cm 98cm
VELUX FK06 66cm 118cm
VELUX FK08 66cm 140cm
VELUX MK27 78cm 62cm
VELUX MK04 78cm 98cm
VELUX MK06 78cm 118cm
VELUX MK08 78cm 140cm
VELUX MK10 78cm 160cm
VELUX MK12 78cm 180cm
VELUX PK25 94cm 55cm
VELUX PK04 94cm 98cm
VELUX PK06 94cm 118cm
VELUX PK08 94cm 140cm
VELUX PK10 94cm 160cm
VELUX SK01 114cm 70cm
VELUX SK06 114cm 118cm
VELUX SK08 114cm 140cm
VELUX SK10 114cm 160cm
VELUX UK04 134cm 98cm
VELUX UK08 134cm 140cm
VELUX UK10 134cm 160cm

How to Find the Size of a Velux Window?

Finding the appropriate code for a Velux window is simple. This is because every window made after 1968 has a helpful label with all the pertinent information printed on it in the upper right corner of the frame. Though, you need to open the window if you want to see the label.

The code on this label identifies the dimensions, frame design, glass type, and opening style of your Velux window. The information present here should be enough to tell you if the window is right for you or not, but if it isn’t, you should always feel free to contact customer support. 


Choosing the right size is paramount when you’re trying to install Velux windows in your home. The size of the windows will impact the functionality, aesthetics, and curb appeal of your home, and it will also impact the usability and practicality of the window as well. In this article, we told you everything you need to know to determine the size of a Velux window. Now it is time to decide whether it is right for you.