How to measure

Precise measurement = perfect installation + shading effect

Measurement videos

Required tools

Using a soft tape measure without pulling it tight can easily result in shorter measurements. This is especially true for width, where the soft tape tends to sag, causing errors.

Steel tape measure

Pen and paper to record measurement results

A friend comes to help you

Three-step measurement formula

Note: If you are installing exterior, you can skip the window depth measurement.

STEP 1

Whdth: Measure at the top, center, and bottom points, and take the minimum.

 

STEP 2

Height: Measure at the left, center, and right points, and take the minimum.

 

STEP 3

Depth: Recess depth minus obstruction depth.

Common obstacles include Window handles, Latches,Lokcks,Winders or cranks.

80% of people make several mistakes

Want to see more FAQs? Scroll down.

1. The tape measure is not level when measuring.

2. Obstacles are ignored when measuring groove depth.

3. Measurement not taken in front of groove.

Having trouble?

If you need assistance, please contact the Brissa team and we'll be happy to assist you.
Email: support@berissablinds.com

FAQ

Can I measure just one single position?

No. For example, if you only measure the width in the middle and ignore inconsistencies between the top and bottom—common in older homes or with uneven walls—this could affect your experience. Please strictly follow the measurement instructions.

Can I use a phone app to measure? What tools do you recommend?

No, phone apps are not reliable for precision and may cause significant errors. We recommend a steel tape measure (with a minimum scale of 1mm). Avoid soft tapes (easily stretchable) or leather tapes (high elasticity). When measuring, ensure the tape is perfectly vertical/horizontal against the window frame to prevent skewed readings.

For inside mounting, do I need to leave extra space in width or height to prevent the curtain from getting stuck?

No. Based on years of industry experience, we’ll 预留 the optimal space during customization to ensure smooth operation. Please note: Do not use your own reduced width/height measurements as the basis for purchase!

Do drill-free products support outside mounting?

No, drill-free products are only suitable for inside mounting.

My windows open inward. Can I choose inside mounting?

No. Inward-opening windows are structurally unsuitable for inside mounting. We recommend outside mounting instead.

Can outside mounting achieve 100% light blockage?

Yes, provided you choose 100% blackout fabric, and the curtain’s width and height fully cover the entire window frame.

Do I need to account for curtain pleats when measuring?

No need to leave extra space. Berissa automatically calculates the pleat ratio based on the curtain type. Simply provide the actual measured width and height of the window to avoid over-sizing from adding extra length on your own.

My window frame is slanted (e.g., a 1-2cm difference between top and bottom width). Which measurement should I use?

For inside mounting, use the narrowest measurement (to ensure the curtain fits into the frame). For outside mounting, use the widest measurement (to ensure full coverage). We recommend outside mounting for complete coverage.

Can I buy new curtains using the exact measurements of my old ones?

We don’t recommend it. Old curtains may have deformed over time (e.g., shrunk or stretched), leading to inaccurate sizes. Additionally, the old mounting type (inside/outside) may not match the new curtains. We suggest remeasuring the actual window dimensions.

If I notice uneven walls (dents or bulges) during measurement, will this affect outside mounting?

Yes. Outside mounting tracks need to sit flush against the wall. Bulges (e.g., nails, peeling paint) can tilt the track, causing light leaks or poor curtain movement. Dents may create gaps between the track and wall. We recommend repairing the wall first before measuring.

Is measuring for motorized curtains different from regular curtains?

No, it’s the same. You only need to ensure the window depth is sufficient, as motorized tracks are wider than standard ones.

I’m not sure whether to choose inside or outside mounting. Do I need to provide measurements for both?

We recommend measuring and labeling both. Provide the inside mounting dimensions (net width/height of the window frame interior) and outside mounting dimensions (wall coverage area outside the frame). If you’re still unsure, contact the Berissa team—we’ll be happy to advise you.

The difference between internal and external installation

Inside mounting emphasizes a "snug, streamlined look." It’s ideal for those wanting a seamless, hidden effect, provided your window frame meets the requirements (sufficient depth). However, it demands high precision in measurements and stricter installation conditions. Its light-blocking ability is weaker than outside mounting: typically, inside-mounted curtains need extra space on both sides for smooth operation, preventing them from getting stuck when opening or closing. This can let light seep through the gaps, so users with high light-blocking needs often pair them with fabric curtains to fix this issue, or opt for outside mounting instead.

Tip: If you choose Berissa curtains, you only need to provide the most accurate inside mounting measurements. Based on our years of experience, we’ll precisely calculate the optimal operating space on both sides for you.

Outside mounting prioritizes "functionality and flexibility." It offers better light blocking and greater versatility, making it suitable for most general scenarios—especially for addressing window frame issues (e.g., insufficient depth or narrowness). However, it takes up more space, and the increased coverage area means the price will rise accordingly.

Inside Mount

Outside Mount