Measure in millimetres
Always.
HELP HUB · MEASURING
Measure once, with confidence.
Every Shutter Pros order is made to your window's exact dimensions. This guide walks you through taking those measurements yourself, clearly and without guesswork, so the shutters you receive fit beautifully from the first fit.
- A rigid tape measure designed for internal measurements
- A pencil
- A notepad
Use a rigid tape measure designed for internal measurements — not a standard flexible tape. Flexible tapes bend and kink inside the recess, and that flex is the most common cause of mis-measurement we see. A rigid internal-measure tape typically costs around £25 and pays for itself on the first window.
Which guide do I need?
You don't need to be an expert. Find the description that matches your window, then follow that section. If you're between two, measure for both and note it on your quote, and we'll help you choose.
Most common
Recessed windows
Your window sits back inside the wall, leaving a sill and a reveal the shutters can sit within.
Flush & sash
Non-recess windows
Your window is flush with the wall, or too shallow to hold a frame inside. Shutters mount on the face.
Angled & curved
Bay windows
Several windows meeting at angles. Measured section by section, with matched heights across the bay.
The six golden rules
Windows are rarely perfectly square. These six habits protect you from every one of those surprises.
Measure everything twice, at three points
Width at top, middle and bottom; height at left, centre and right. If your two passes disagree, measure a third time — never guess.
Use the smallest figure
For each dimension.
Measure where the shutter will actually sit
For recess fits, measure at the depth the frame will be fixed — reveals are rarely perfectly straight front to back, and a measurement at the wrong depth is a wrong measurement.
Made to the exact size you enter — nothing is deducted
Most suppliers quietly take 4–5mm off your measurements; we don't, because you stay in control. Our recommendation: once you have your smallest true measurement, allow 3mm off width and height as fitting tolerance. The final figure is always your decision — whatever you enter is precisely what you'll receive.
A close fit is the goal
If a high spot in the plaster catches, easing back a little plaster or paint takes minutes — trimming a finished shutter is a job nobody wants.
Write, don't remember
Note each figure down the moment you take it, labelled clearly, such as 'living room, width top / middle / bottom'. It's a small discipline that prevents the most common ordering mistakes.
Taking your measurements
Open the section that matches your window. The six golden rules run through them all.
The most common style of UK window: the glass sits back inside the wall, creating a recess (the reveal) with a sill at the bottom. Shutters can be fitted neatly within it for a built-in look.
- Width. Measure the full width of the reveal, plaster face to plaster face, at the top, the middle and the bottom. Record all three; keep the smallest.
- Height. Measure from the sill up to the top of the reveal at the left, the centre and the right. Record all three; keep the smallest.
- Depth. Your reveal needs to be at least 55mm deep for shutters to sit inside it (an inside mount). Anything shallower is mounted on the wall face instead, as covered under Non-recess windows above.
- Check for square. Measure corner to corner, both diagonals. If they differ noticeably, your window is slightly out of square, which is perfectly normal in older homes. Just note it on your quote so we can allow for it.
Handles and obstructions: note anything that projects into the opening, such as window handles, locks or trickle vents, and how far the handle sticks out, so we can make sure the panels swing and the louvres turn freely.
Some windows sit flush with the wall, or the reveal is too shallow to hold a frame inside. Sash windows often fall into this group. Here the shutters mount on the wall face, framing the window rather than sitting within it.
- Decide your coverage. Because the frame sits on the wall, you choose how much of the surrounding wall it covers. A little overlap on each side gives a clean, generous finish and blocks side light.
- Width. Measure the width of the opening, then add your chosen overlap to each side. Note both the opening size and your intended overall width.
- Height. Measure the height of the opening and add the same overlap top and bottom, unless a sill or floor sets the lower limit.
- Note what's around it. Skirting boards, deep sills, coving or nearby walls can all affect where the frame sits. A quick note or photo of anything close by helps us confirm the fit.
Matching neighbours: if two flush windows sit side by side, keep the heights identical so the finished shutters line up perfectly.
A bay is simply several windows meeting at angles: square, angled (splayed) or curved. Each section is measured on its own, exactly as you would a single recessed or non-recess window, with a little extra care where they meet.
- Number each section. Sketch the bay from above and label the sections left to right. Measure and record each one separately against its number.
- Measure every section in three places. The six golden rules apply to each pane of the bay, just as they would on their own.
- Match the heights. Give every section in the bay the same height. Even a few millimetres of difference can leave neighbouring shutters looking slightly mismatched.
- Note the angles. Tell us whether the bay is square, splayed or curved, and roughly the angle where sections meet. This lets us prepare the joining posts correctly.
A sketch is worth a hundred numbers: a simple top-down drawing with your section numbers and angles marked makes a bay quote far quicker and more accurate.
HOW WE WORK
We supply. You fit. We're with you throughout.
Shutter Pros is a supply-only specialist. Your shutters are made to the precise measurements you provide and are ready for you to collect and fit yourself, with a clear step-by-step guide for doing so. If a measurement leaves you uncertain, send it over with a photo before you order. A second pair of expert eyes costs nothing and saves any doubt.
Read the Self-Fitment Guide →Measured up? Let's get your price.
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