How to Measure Venetian Blinds: Slat Size, Headrail, and Getting the Fit Right

What Measurements Are Required for Venetian Blinds?

For venetian blinds, the width measurement refers to the width of the headrail, and the drop measurement is taken from the top of the headrail to the underside of the bottom rail. You can provide either recess size or blind size.

As with all recess fitting, take three width measurements at the top, middle, and bottom of the recess, and two drop measurements at the left and right. Enter the smallest of each.

Does Slat Size Affect the Measurements?

The website currently offers 25mm slats for venetian blinds. The slat size does not change the measurements you are required to take. However, it is worth being aware that narrower slats create a more fine-grained light filtering effect, while wider slats — where available — offer a bolder visual style and broader light control.

What Are the Size Limits for Venetian Blinds?

Manual venetian blinds:

• Minimum width: 300mm
• Maximum width: 3600mm
• Minimum drop: 300mm
• Maximum drop: 3150mm

Electric venetian blinds:

• Minimum width: 540mm
• Maximum width: 2591mm
• Minimum drop: 300mm
• Maximum drop: 3048mm

If your window falls outside these limits, contact estimates@newblinds.co.uk to discuss options.

Do Control Options Affect the Measurements?

No. Whether you select cord or wand control, the measurements you provide remain the same. You specify your preferred control method during the ordering process.

When Should a Wide Window Be Split Across Multiple Venetian Blinds?

If the window width approaches or exceeds the manual maximum of 3600mm, splitting across two blinds is the appropriate approach. As with roller blinds, measure each section individually and order them separately. Contact the team if you need assistance planning how to divide the opening.