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How to Measure for Roof Lantern Blinds

Roof lantern Blinds

At Skylight Blinds Direct, we specialise in self-fit roof lantern blinds that offer perfect light control, privacy and thermal insulation — and best of all, you don’t need a professional to install them.

But before you get your hands on one of our made-to-measure Honeycomb Openview Blinds, you’ll need accurate measurements. Don’t worry — it’s easier than you think.

📐 Step-by-Step Guide to Measuring For Your Roof Lantern Blind

✅ Step 1: Decide Where You’ll Fit the Blind

First, decide where in the recess the blind will sit. We recommend fitting within the recess about 3/4 of the way (but there are no hard and fast rules- we also recommend leaving at least 15cm above the blind between the blind and the glass - for access reasons).

✅ Step 2: Mark the Recess

Use a pencil to lightly mark the point inside the recess where the blind will be installed. This marks the place that you will measure between.

✅ Step 3: Measure in 3 Places

Using a steel tape measure, take the width and length measurements at three different points. This ensures that we account for any minor variations in your window structure (which are very common).
📏 Measure in millimetres (mm) and do not make any deductions — we’ll take care of that. This is known as the Recess Size.

Width: Measure across the window in three places (top, middle and bottom).
Length: Measure down the window in three places (left, middle and right).

✅ Step 4: Know Your Sizes? Use “Exact Size” Option

If you already know the exact finished blind size you require (i.e. you’ve accounted for recess space or want a surface fit), you can select “Exact Size” when ordering.
In this case, give us the exact width and length 3 times each — no deductions will be made.

Why Measuring Accurately Matters

Roof lantern blinds need to fit perfectly to:

Block glare and heat in summer
Retain warmth in winter
Deliver that flush, custom-fitted look
Maximise the efficiency of blackout or thermal honeycomb fabrics

Pro Tip: Take Your Time

Double-check your measurements. Write them down and confirm before entering them at checkout. If you’re unsure, our team is always happy to help.

Still Unsure?

We’ve helped thousands of UK homeowners measure and install their own roof lantern blinds. If you'd prefer a quote first, use our famous "tin can" floor method for a quick estimate — just map the corners out on the floor with four tins of beans and measure between them!