How to Measure Your Windows for Blinds

Bad measurements can ruin a football game. Make a suit too tight or loose. Render your new window treatments unsatisfactory or even unusable.

Every great window treatment starts with a precise height, width, and depth assessment. Without accurate measurements, you risk ordering window covers that don’t fit, look good, or provide the privacy and light control you need. You could waste considerable time and cash on your “cost-cutting” DIY effort.

A professional installation is always your safest bet, but following the guidelines in this blog, you should be able to measure your new blinds for a perfect fit.

Tools You Need

• A steel tape measure
• Pen and paper for jotting down measurements
• Step stool or ladder, if needed
• Measuring guide (provided by the manufacturer of your blinds)

Getting Started with Window Measurements

Are you mounting your blinds inside the window frame or outside? Each option has its own benefits and measuring techniques.

• Blinds sit within the window frame for an inside mount, providing a clean and trim look. Inside mounting works best for windows with enough depth to accommodate the blinds.
• Blinds are attached to the wall above or outside the window frame for an outside mount. Choose this option for windows without sufficient depth or uneven frames.

Measuring for Inside Mounts

Vertical Blinds

• Measure the width of the window frame at three points: top, middle, and bottom.
• Record the shortest measurement to ensure a snug fit.
• Next, measure the window’s height from top to bottom at three places: left, center, and right.
• Again, record the shortest measurement for a perfect fit.

Horizontal Blinds

• Start by measuring the inside width of your window frame from top to bottom in three spots: left, center, and right.
• Record the narrowest measurement for an accurate fit.

Measuring for Outside Mounts

Vertical Blinds

• Measure from the outside edge to the outside edge of your window frame at its widest point.
• Record the width of the frame.
• Next, measure from the top of your window frame to where you want your blinds to hang.
• Record this height measurement.

Horizontal Blinds

• Measure from the outside edge to the outside edge of your window frame at its widest point.
• Record this width measurement.
• Next, measure from the top of your window frame to where you want your blinds to hang and record this height measurement.

Avoiding Mistakes & Ensuring Coverage

• Consider adding an extra inch to your measurements for maximum coverage and light blockage.
• If you have multiple windows next to each other, measure each separately, as they may vary in size.
• Keep your tape measure straight and level. This prevents inaccuracies caused by angled or slanted measurements.
• Always round down to the nearest 1/8 inch rather than rounding up so your blinds will fit snugly.
• Double-check all of your measurements before ordering or cutting any blinds.

FAQs: Measuring Windows for Blinds

Q: Can I measure windows myself, or should I hire a professional?

Most people can measure their own windows with careful attention to detail. However, hiring a professional guarantees accuracy.

Q: How do I decide between inside and outside mounts?

Consider your aesthetic preferences and the depth of your window frame. Inside mounts offer a clean look, while outside mounts provide more coverage.

Q: How do I avoid light gaps with outside mounts?

Add extra width and height to your measurements to cover light gaps and enhance privacy.

Q: Should I measure each window separately?

Yes, measure each window individually to account for variations in size and ensure a perfect fit.

Q: What should I do if my window frame is not perfectly square or has an uneven surface?

This is a common problem. For inside mounts, always use the smallest measurement for width and height. For outside mounts, account for these variations by measuring at several angles and adding extra width to the blinds.

Q: How do I measure windows with obstructions like handles or locks?

When measuring for inside mounts, subtract about 1/2 inch from the width measurement to allow for any obstructions like handles or locks. Verify that the blinds will hang freely without interference. This is less of an issue for outside mounts, as the blinds typically extend beyond the frame.

Q: What if my window depth is insufficient for inside mounts?

Then you’re a candidate for an outside mount. This type of installation doesn’t rely on the depth of the frame and allows the blinds to be mounted directly on the wall or ceiling.

Q: Can I use the same measurements to replace old blinds?

We advise remeasuring to confirm accuracy. Window frames or the surrounding woodwork can warp or change over time, leading to discrepancies that might cause a poor fit for new blinds.