How to measure a window for shutters

There are several different factors to consider when measuring a window.

Before you start

You need to know where the shutter frame can be fitted in your recess as you will need to measure just in front of this position. You also need to check the handle protrusion and if this will affect the louvre blades tilting.

There are several places that you can install a shutter frame; up close to the window frame, halfway in your recess – to miss handles and plastic trims – or right at the front of the recess.

The recess can be angled, so it’s very important to measure in the correct place.


Decide the design of your shutter so that you know whether you’re measuring for middle rails, Tposts, or neither.

Measuring for these features should start from the window sill up to the centre of any mid rails or Tposts, or from the left of the recess to the centre of each Tpost/vertical upright.


Primarily you need to measure the main width and height of your opening recess and you need to do this in a few places to work out the smallest width and smallest height to ensure the shutter frame fits within your opening.

You should check how level your window is by using a spirit level or by measuring diagonally across the window recess. How level or straight your window is will ultimately dictate how much fitting clearance you can allow.

Once you have measured your window, you need to deduct some fitting clearance. This varies for each style of fitting and it’s extremely important to get this right. We have put together a measuring video guide that demonstrates exactly where to measure for each design, rail height and Tpost options, and what fitting deductions to make.

Free video guides

For the best advice we suggest watching these free measuring video guides.