How to Measure for Shutters

Measuring your windows for shutters is much easier than most people expect. With a tape measure, a few notes, and this guide to help you, you’ll be able to gather the sizes we need to give you an accurate quote.

We’ve written this guide in the same way we approach every ShuttersUp project: practical, helpful, and with your best interests at heart. And remember, whatever you measure today is just for quoting. Before anything is made, one of our trained surveyors will visit your home and take precise manufacturing measurements. Nothing is left to chance.

You’re in safe hands. This guide simply gives you a head start.

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⏱ Allow around 10–15 minutes per window · 📏 Tape measure & notepad at the ready

Why Accurate Measuring Matters

When you send us your measurements, it helps us work out:

  • The most suitable shutter style for your window
  • Whether an inside or outside mount will work best
  • The correct frame type
  • A quote that reflects the look and finish you want

Accurate measurements help us get your quote right from the start, which saves time and helps you plan your project.

But please keep this in mind: no one gets it perfect the first time, and that’s completely fine.

Your measurements help us understand your window, but they are never used to make your shutters.

Our surveyors take the final, technical measurements in person. It’s all part of making sure the shutters are truly tailored to your home.

What You’ll Need

A few everyday items are more than enough:

  • A steel tape measure (that remains rigid and accurate)
  • A pencil
  • A piece of paper, or your phone notes
  • Good natural daylight
  • Optional: a second person to help hold the tape

Understanding Recess, Frame Position & Your Window Type

Before you start measuring, take a moment to think about where you’d like your shutters to sit. This affects which measurements we use, and helps ensure everything fits neatly and functions properly.

Inside Mount (Inside Recess)

This means the shutters sit inside the existing window recess.

Great if you want:

  • A tidy, built-in look
  • A frame that sits flush with your window
  • Shutters that don’t project into the room

You’ll just need to make sure there’s enough depth inside the recess for the frame and louvres.

Outside Mount (Face-Fit)

This means the shutters sit outside the recess, either on the wall or on the window trim.

This is often best when:

  • Handles, vents or tiles stick out
  • Your recess depth is quite shallow
  • You prefer a more decorative frame that covers the whole window area

Both options can look great. The most important thing is choosing the one that works best for your space.

Illustration showing inside mount and outside mount shutters
Inside Mount vs Outside Mount

Step-by-Step: How to Measure for Window Shutters

Before you start measuring, take a moment to think about where you’d like your shutters to sit. This affects which measurements we use, and helps ensure everything fits neatly and functions properly.

Step 1: Measure the Width

Whether you’re measuring inside or outside the recess, take the width in three places:

  • Across the top
  • Across the middle
  • Across the bottom

Because most windows are slightly uneven (which is completely normal), this helps us understand the “true” size.

  • For an inside mount, record the smallest measurement
  • For an outside mount, record the largest measurement

Step 2: Measure the Height

Just like the width, measure the height in three places:

  • Left side
  • Centre
  • Right side

Again:

  • For an inside mount, use the smallest measurement
  • For an outside mount, use the largest measurement

If your window has a sill that sticks out, measure to the highest flat point.

Step 3: Optional – Check the Diagonals

This part is optional, but helpful.

Measure diagonally:

  • From the top-left corner to the bottom-right
  • From the top-right corner to the bottom-left

If these numbers don’t match exactly, it simply means your window isn’t perfectly square. Most windows aren’t, especially in older UK homes. Knowing this helps us choose the right frame template, so your shutters fit neatly and operate smoothly.

Window Width Measurements
Window Width Measurements
diagonal-window-measurements
Window Height Measurements

How to Measure for Bay Window Shutters

Bay windows are one of the areas where shutters offer true benefits. They add warmth, privacy, and structure without blocking the natural shape of the space.

Here’s how to measure them in their different styles.

Angled Bay Windows

These have angled sides leading into a central panel.

How to measure an angled bay:

  1. Measure each window section individually
    Measure the width of each section (top, middle, bottom), and record the smallest value.
  2. Measure the height of each section
    Again, using left, centre, right, and noting the smallest.
  3. Note the mullions
    These are the points where each window section meets. Mark where each one falls so we understand the layout.
  4. Angles (optional)
    If you’re able to measure the angle between sections, that’s helpful, but not essential. Our team can work this out during your survey.
angled bay windows
Angled Bays Window

Box Bay Windows

Box bays sit at 90-degree angles, so they’re simpler to measure.

How to measure a box bay:

  • Measure each section just like you would a standard window
  • Width: top, middle, bottom – record the smallest
  • Height: left, centre, right – record the smallest
  • Repeat this for each of the three window sections
box bay window shutters
Box Bay Windows

How to Measure for Plantation Shutters or Shutter Blinds

The process of measuring plantation shutters is very similar to the steps above, but here are a few things to keep in mind.

What to measure:

  • Width: measured at top, middle, and bottom
  • Height: measured at left, centre, and right
  • Depth: this tells us how well the louvres will clear your window frame
  • Obstructions: note any handles, locks, or vents

Some shutter styles require more depth than others, so if your recess is shallow, an outside mount may be the better option. This is something we can help you decide once we’ve seen your measurements.

If you’re still deciding which shutter style is right for your space, you can explore some of our popular ranges, including our Faux Wood Shutters and our made-to-measure Perfect Fit Shutters.

plantation shutters
Plantation Shutters

Measuring Tips to Avoid Common Mistakes

Here are a few friendly reminders we’ve picked up from years of experience:

  • Measure in millimetres – they’re more accurate
  • Write every measurement down clearly
  • Don’t round numbers up or down
  • Use a metal tape measure, not a flexible one
  • Make sure you measure the inside edge when doing inside mounts
  • Don’t mix inside and outside measurements
  • Check depth if you want an inside mount
  • Take your time – there’s no rush
  • Measure each window separately, even if they look the same

These little details help us give you the most accurate quote possible.

What Happens After You Submit Your Measurements?

Once you’ve sent your measurements through the quote form:

  1. We review your notes carefully
    We look at your window type, your chosen style, and any obstructions you’ve mentioned.
  2. We prepare a personalised quote
    You’ll always receive a clear, transparent breakdown based on your measurements and preferences.
  3. We arrange a professional survey
    If you’re happy with your quote, we’ll book a survey at a time that suits you. This is when we take the exact manufacturing measurements.
  4. Your shutters are made to order
    Every shutter is crafted to match your exact window shape, size and frame layout.
  5. We install them with care and precision
    Our fitting team checks every panel, hinge and louvre, making sure everything operates exactly as it should.

We handle all the technical parts so you can simply enjoy choosing the shutters that feel right for your home.

Frequently Asked Questions

What if my measurements aren’t perfect?

Don’t worry, your measurements are only for quoting. Our surveyor visits your home later and takes precise, final sizes before your shutters are made.

Should I use inches or millimetres?

We always recommend measuring in millimetres. They’re far more accurate than inches and help ensure your quote and final survey measurements line up correctly,

Can I still get a quote if my window is an unusual shape?

Yes, absolutely. We regularly fit shutters to special-shaped windows. You only need rough measurements for your quote. Our surveyor handles the technical details later.

Do I need different measurements for plantation shutters?

No, the process is the same. The only extra thing to check is recess depth, as larger louvres need space to open and close properly.

How do I measure bay windows?

Measure each bay section at the top, middle and bottom to spot any variations. Our guide above explains angled and box bays in simple steps.

What if there are handles, vents or tiles in the way?

Just note anything that sticks out, such as handles or tiles. This helps us understand your space and recommend the most suitable shutter frame style.

Do you check measurements before making the shutters?

Yes, always. Your shutters are only ordered after our surveyor visits your home, confirms every measurement, and ensures the design will fit perfectly.

Can someone from ShuttersUp measure for me?

Of course. Many people prefer this. We’re happy to arrange a professional home survey so we can take accurate measurements and guide you through options.

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