01
Use a metal tape
Keep it straight and measure the clear recess rather than the glass or outer trim.
onerest
Excellent
Measurement guide
Check your recess, measure three widths and three heights, then let our assistant choose the right order size.
Measure my window
Before you begin
Keep it straight and measure the clear recess rather than the glass or outer trim.
The fitting zone must be at least 3 cm deep and clear of handles, locks and vents.
Measure twice, keep one decimal place in centimetres and never round early.
Interactive measuring assistant
Enter three width and three height readings. We will select the smallest values for the closest fit.
About 3 minutes
Before you start
Use a rigid metal tape and measure the clear opening, not the glass. Keep the tape straight and do not make your own deductions.
Your preferred unit
You will need
A metal tape measure, a pencil and somewhere to record six readings.
Set upThis assistant is for a straight, unobstructed inside recess. Bay windows, unusually uneven openings or protruding fittings should be checked with support before ordering.
The sizing rule
Window openings are rarely perfectly square. Using the smallest reading on each axis helps the made-to-measure frame sit within the clear opening.
The assistant does not apply a hidden deduction. It converts inches when needed, selects the smallest valid readings and rounds the final centimetre dimensions to the nearest millimetre.