Choosing roller blinds is easy, but getting the perfect fit depends entirely on accurate measurements. Whether you prefer an inside mount for a neat look or an outside mount for better light control, proper measurement ensures smooth installation and a polished finish.
This simple, step-by-step guide from Katha Furnishings will help you measure your windows with confidence.
1. Decide Between Inside Mount and Outside Mount
Before you begin measuring, identify how you want your blinds to be installed.
Inside Mount
The blind fits within the window frame.
Best for: modern, minimal aesthetics.
Benefits:
- Clean, built-in look
- Saves wall space
- Ideal for deep window frames
Requirement:
The frame must have enough depth to accommodate the roller mechanism.
Outside Mount
The blind is installed on the wall above or around the window frame.
Best for: maximum light blockage and small windows.
Benefits:
- Makes windows appear larger
- Covers gaps for blackout needs
- Works even if the frame depth is shallow
2. How to Measure for Inside Mount Roller Blinds
Use a steel measuring tape for accuracy. Measure in millimetres or inches—just stay consistent.
Width Measurement
Measure the width of the window at three points:
- Top
- Middle
- Bottom
Use the smallest measurement for ordering the blind. This prevents the blind from rubbing against the inside frame.
Height Measurement
Measure from the top inside edge to the bottom inside edge at three points:
- Left
- Middle
- Right
Use the largest measurement for accurate coverage.
Depth Check
Ensure you have sufficient frame depth for your blind’s bracket and fabric roll.
If unsure, you can always consult Katha Furnishings for guidance.
3. How to Measure for Outside Mount Roller Blinds
Outside mount blinds cover the window frame entirely, so measurements must extend beyond the opening.
Width Measurement
Add at least 2–3 inches (5–7 cm) to each side of the window.
This ensures full coverage and better light control.
For example, if your window width is 40 inches:
40 + 3 + 3 = 46 inches blind width.
Height Measurement
Measure from the top of where you plan to mount the blind (usually 2–3 inches above the frame) to the desired bottom length.
For blackout blinds, extend the blind 4–6 inches below the window.
4. Measure the Mounting Height Carefully
If mounting above the frame, keep a consistent height across all windows for a neat finish.
For tall or large windows, higher placement creates the illusion of taller walls.
5. Common Measurement Mistakes to Avoid
- Measuring only once
- Switching between units midway
- Ignoring frame depth
- Forgetting extra space for outside mounts
- Assuming all windows in a room are the same size
Double-check measurements to save time and avoid resizing issues.
6. When Should You Get Professional Measurement?
If your windows are:
- Arched or angled
- Bay windows
- Extra-large or floor-to-ceiling
- Have obstacles like handles or grills
Professional help ensures precision.
You can also book a measurement consultation with Katha Furnishings to avoid guesswork.
Conclusion
Measuring your windows correctly is the first and most important step to getting perfect roller blinds. With the right measurements, you ensure better function, smoother installation, and a flawless fit that enhances your interiors.
Explore our Roller Blinds Collection or read our guide on Choosing the Right Roller Blinds for Your Home to continue your selection journey.
FAQs: Measuring for Roller Blinds
1. What tools do I need to measure for roller blinds?
A steel measuring tape, a pencil, and a notepad are enough. Avoid cloth tapes because they are less accurate.
2. Should I round up or round down measurements?
For inside mounts, always round down to ensure the blind fits correctly. For outside mounts, round up for full coverage.
3. How do I know if my window frame has enough depth?
Most roller blinds need 2–3 inches of depth. Measure from the inside face of the frame to the window glass.
4. Can I install roller blinds on UPVC or aluminium windows?
Yes. Both inside and outside mounts work—just ensure bracket placement is secure.
5. Do all windows in a home need the same blind size?
No. Even seemingly identical windows can differ by a few millimetres. Always measure each window separately.
6. Should I choose inside or outside mount for blackout blinds?
Outside mount offers better light control and is recommended for bedrooms and media rooms.