How do I measure my windows for curtains and blinds?

The thought of measuring your windows to buy curtains and blinds might not exactly have you jumping for joy but it's really quite easy. To make sure you've got the numbers correct, we've created a simple step-by-step guide that runs through all the little details to get your measurements perfect.

Before you start

Make sure you have the following equipment:

  • A metal tape that measures in millimetres (never use fabric tape as it can stretch and give you an inaccurate reading)
  • A pencil and paper to note down your measurements
  • A spirit level, if you are hanging more than one set of curtains or blinds
  • A step ladder
  • Someone to help you
  • A pencil to fill out the Bring Your Own Measurements form

Windows are not always square - especially older windows - so we suggest you take a number of measurements at different points across the window to allow for variations. Similarly, never assume all windows in your house are the same. Measure all windows individually and measure them twice or, better still, get a friend to take the second lot of measurements, just to be sure.

Note: If you bring your measurements into a Spotlight store to place a Made to Measure order, we'll give you an extra 5% discount on your purchase.

This offer is only available on curtains and indoor blinds. Outdoor blinds and shutters are excluded.

Shop Curtains & Blinds

Measuring For Curtains

Have a think about how your curtains will hang:

Will they be sitting in front of window with - or without - architrave? Or will they be hanging inside the space of a recessed window?

Once you have made your decision, you can measure your windows for curtains by following the basic instructions for measuring for blinds.

You will need to alter these measurements depending on whether you want pelmets, curtain rods or tracks, or other functional and design considerations, such as trims and tassels, that may influence the drop and overall dimensions of your curtains.

A Spotlight specialist will be able to help make these additions and alterations to your measurements in order to accommodate your specific curtain needs.

Measuring For Blinds

Start by looking at your window to decide where you want your blinds to go - recess or face fix.

To determine whether the blind is more suitable for a recess or face fit, think through the following:

  • What is the depth of the recess? Blinds will need to be between 30mm to 100mm for the headrail, dependent on the product.
  • Are there any obstructions, such as window winders, that will get in the way?
  • What is the frame of the window and could it affect how the blinds will hang?
  • What is the window type - louvre, hinged, sash, sliding doors and so on?

Sometimes, you will need to add or deduct from the measurements but it is just as easy to follow the steps and then a Spotlight specialist can customise the measurements when you bring them to the store.

Measuring Your Curtains
Measuring Your Blinds

Face Fix With Architrave

Measure the width of the top of the window from architrave to architrave. Measure the drop from the top of the architrave edge to the bottom of the sill or the floor. Measure on the left and right of the window to check if the window is even.

You should add extra to the measurement if the window does not extend to the floor. For example, blinds are best extended for an additional 150mm below the sill to minimise light seepage. On the other hand, curtains can vary wildly in length, depending on the style, type of fabric, function, etc.

Face Fix Without Architrave

Measure the width from window edge on the left to the window edge on the right at the top of the window. Extend the measurement by 50-100mm on each side to minimise light seepage and ensure proper fixing of the blind.

Measure the drop from window edge at the top to the bottom of the window or floor. Measure on both the left and right of the window to check if it is even.

Make sure you also add 100mm to the top of the measurement to allow for the top fixing and, if the window does not extend to the floor, it's best to add an extra 150mm below the sill to minimise light seepage.

Face Fix With Architrave
Face Fix Without Architrave

Recess Fit


Measure the width at three points across to check the window is square and provide the smallest/shortest measurement. Similarly, measure the drop at three points and provide the smallest/shortest measurement.

Note: the manufacturer of the blinds will allow for the brackets from the measurements you provide.

Face fix your blinds to minimise light seepage and the imperfections of your window. Brackets are usually positioned one at each end but some wider blinds, particularly venetians, need an additional centre bracket for support.

Keep in mind, if you choose recess (inside) fit blinds, light will show through gaps on either side. For greater blockout, face fix is the way to go.

Also, if there are large variations in either your width or drop measurements, face fixing your blinds will help minimise light seepage and any window imperfections.

Shop Curtains & Blinds

Recess Fit For Your Window Furnishings

Want to look at more curtain & blind options?

Check out Spotlight's range of Curtains & Blinds online, visit your local store or contact one of our experts for further assistance.

Still not sure what to do with your window furnishings? Our Made to Measure service makes choosing your curtains, blinds, shutters and outdoor awnings easy.

Shop Curtains & Blinds



Get VIP discounts, attend exclusive events and more