Angled Bay Window Measuring Guide

What you will need:
• 2 pieces of A4 or A5 paper or card
• A metal tape measure
• A pencil
• A ruler

Angled Bay Measuring Blind Position


If you have any handles or vents on the windows, measure in millimetres how far out from the window frame they protrude. You’ll need to add this measurement to the ‘depth’ of your blind in the next step.

Window Handle Projection

The ‘depth’ of your chosen blind type is shown in the table below. This depth is simply the distance your blind will protrude from where it is fitted. You’ll need to know this depth to make the correct allowance when measuring.

Blind Type   Depth
Roller Blinds (Face-Fix)   70mm
Roller Blinds (Top-Fix)   50mm
25mm Real & Faux Wood Blinds   55mm
35mm Real & Faux Wood Blinds   55mm
50mm Real & Faux Wood Blinds   65mm
25mm Aluminium Venetian Blinds   30mm
Roman Blinds   50mm
Vertical Blinds   75mm

Add these two measurements together and note down the result as Dimension ‘A’. If there are no handles or any other obstructions on the windows, just use the blind ‘depth’ as Dimension ‘A’.

Depth Calculation


Step 1

Take your 2 pieces of paper and place them edge to edge. Using a ruler, measure Dimension ‘A’ from the back edge and make a mark on both pieces of paper.

Mark the Blind Depth Deduction onto the Pieces of Paper

Step 2

Place the pieces of paper on the window-sill, one either side of the bay window corner and against the window frame. Slide them towards each other until the two marks meet up.

Slide the two Pieces of Paper into the Bay Corner


Step 3

Take the pencil and make a mark on the window-sill at the exact point where the paper meets the window frame. Repeat steps 2 and 3 for each corner of your bay window.

Mark Where to Measure to on the Window-Sill

Step 4

Measure precisely between each set of marks you have made and note these measurements down. These are the ‘exact’ widths of the blinds you will need to order.

Measure the Width of the Bay Window Blinds with a Tape Measure


Step 5

For the drop of your blinds, simply measure from the top of where you want the blinds to fit, down to where you would like the bottom of the blinds to rest (this is usually the window-sill, if you have one). Take this measurement in at least three places across the bay window and use the smallest measurement.

For Vertical Blinds only, reduce this measurement by 12mm to ensure the fabric louvres don’t drag or sit on the window-sill.

Note, all of the blinds for your bay window should be ordered as ‘Exact Size’.

Measure the Drop of the Bay Window Blinds