Plantation shutter louvre sizes explained: 64mm vs 76mm vs 89mm vs 114mm

Choosing between plantation shutter louvre sizes is easier once you know what the measurement changes. The louvres are the horizontal slats that tilt open and closed. Their size affects how much of the window you can see through. How daylight enters the room and how detailed or minimal the shutters look.

Shutters365 offers four sizes: 64mm, 76mm, 89mm and 114mm. There is no single best option for every home. The right choice depends on your window proportions, the room, the view and the look you prefer.

The quick answer: Choose 64mm for a more traditional, detailed appearance. 76mm for a versatile middle option. 89mm for a balanced view and modern finish; or 114mm for the clearest view across a large window. If you are still deciding whether shutters are right for the room, explore the complete range of made-to-measure plantation shutters.

This guide focuses only on choosing the louvre size.

What does the louvre size change?

The size is measured across the face of each louvre. A shutter panel needs more 64mm louvres than 114mm louvres to cover the same height. This changes four things.

The view through an open shutter

Larger louvres create wider spaces between the slats when they are fully open. As there are also fewer slats in the panel, less material interrupts your view. If you want to look out over a garden or keep a large window feeling open, 89mm or 114mm may suit you.

The amount of daylight

Wider openings normally allow more daylight into the room when the louvres are open. Smaller sizes give you finer visual spacing but place more slats across the window.

Privacy while the louvres are tilted

Smaller louvres can make it easier to break up the direct view through a street-facing window while still admitting some light. However, size alone does not guarantee privacy. The louvre angle, height, and distance from light all affect what someone can see.

When the louvres are fully closed, every size is designed to overlap and cover the window. The main privacy difference appears when the slats are partly or fully open.

The overall appearance

More narrow slats create a detailed, traditional rhythm. Fewer wide slats look cleaner and more contemporary. Window size matters too: a louvre that feels bold and balanced on a tall picture window may dominate a small window.

64mm vs 76mm vs 89mm vs 114mm at a glance64mm louvres: traditional appearance and closer privacy control

64mm louvres: traditional appearance and closer privacy control

The 64mm option has the greatest number of slats across a Shutters365 panel. This gives the shutter a more detailed and traditional appearance, which can sit naturally in period homes and rooms with smaller-scale features.

It is also worth considering where the window faces. On a bedroom or street-facing window, the smaller gaps between partly open louvres can help interrupt direct sightlines. You can adjust the angle in smaller visual steps while keeping some daylight in the room.

Choose 64mm when:

1. your window is small or narrow;
2. you prefer a classic shutter appearance;
3. privacy while the louvres are tilted matters more than an uninterrupted view; or
4. you want the louvres to feel proportional to detailed or period interiors.

The trade-off is that more slats remain in your line of sight when they are open. On a wide or tall window, this can make the shutter look busier than a larger louvre size.

76mm louvres: the versatile middle option

The 76mm louvre sits comfortably between the traditional 64mm and the more open 89mm. It has fewer visual lines than the smallest size without creating the bold scale of the larger options.

This makes 76mm useful for standard UK windows and for homeowners who want a clean finish that does not feel strongly traditional or ultra-modern. It can work across bedrooms, living rooms and dining rooms where a balance of privacy, light and proportion is the priority.

Choose 76mm when:

1. you want a flexible middle size;
2. 64mm feels too detailed but 89mm looks too wide;
3. your window is average in scale; or
4. you prefer natural hardwood shutters.

There is one important product restriction: the Shutters365 designer currently marks 76mm as wood only. Select Paulownia or Basswood before testing this size in the preview.

89mm louvres: balanced light and view

Shutters365 labels 89mm as its balanced option. The wider slats reduce the number of lines across the window and create a clearer view when open, but they are not as visually dominant as 114mm louvres.

This size can be a strong choice for a living room, dining area or medium-to-large window where natural light and the outside view both matter. Its cleaner spacing also suits contemporary interiors without making the shutters look oversized on many everyday windows.

Choose 89mm when:

1. you want more daylight and a clearer outward view;
2. your window is medium or large;
3. you prefer a simple, contemporary finish; or
4. you want a practical compromise before moving to the widest option.

On an angled bay, check that the louvres can rotate without meeting a window handle or the louvres on the next section. The design should follow the individual proportions and angles of your bay window shutters, rather than using size alone as the rule.

114mm louvres: large windows and contemporary rooms

At 114mm, these are the widest louvres in the Shutters365 designer. A panel uses fewer slats, giving you the clearest view and the most minimal appearance of the four options when they are open.

The size works particularly well on tall windows, wide picture windows and rooms where the window is a major architectural feature. It can make a large shutter installation feel calmer because there are fewer horizontal lines across the glass.

Choose 114mm when:

1. preserving a garden or landscape view is a priority;
2. the window is tall or visually substantial;
3. you want a bold, modern appearance; or
4. the room has enough scale to carry wider louvres.

Large louvres need more room to rotate. Before ordering, consider the depth of the recess and the position of projecting window handles. The widest size may also look out of proportion on a short or narrow window. Use the designer preview and let the Shutters365 team review the final configuration rather than relying on window height alone.

Which louvre size suits each window and room?

Use the table below as a starting point, not a fixed specification. Two windows of the same height can need different choices because their width, panel layout, handles and surroundings are different.

In bathrooms and other moisture-prone rooms, choose the appropriate material before choosing the slat width. Shutters365 recommends waterproof PVC for these spaces, while its 76mm option is wood-only. See the dedicated bathroom shutters page for the room-specific product choice.

Do materials limit the louvre size?

Yes, one size has a clear restriction in the current Shutters365 designer: 76mm louvres are available with wood only.

Shutters365 offers PVC, Paulownia hardwood and Basswood hardwood. Paulownia is lightweight and particularly well suited to large windows and wide louvres. Basswood provides a fine-grain hardwood finish, while waterproof PVC is intended for bathrooms, kitchens and other high-moisture rooms.

Material, window dimensions and panel configuration can affect which combinations are suitable. The online designer updates the options around your selections, and a Shutters365 expert checks the design and measurements before production. For a wider comparison of the three materials, read the guide to PVC vs hardwood shutters.

Compare every size on the same window

Louvre sizes are difficult to compare across photographs of different rooms. The fairest test is to keep the window, panel layout, colour and camera position exactly the same and change only the louvre size.

In the Shutter designer tool, enter the same window details and switch between 64mm, 76mm, 89mm and 114mm. Watch three areas in the preview:

1. how many horizontal lines cross the window;
2. how open or enclosed the view feels; and
3. whether the louvre width looks balanced with the height and width of the window.

If you are deciding between two neighbouring sizes, compare those two first. Most choices become clearer when the only changing feature is the slat width.

Which plantation shutter louvre size should you choose?

Start with the result you want from the window:

1. Choose 64mm for a traditional look and closer control of sightlines.
2. Choose 76mm for a versatile middle size in Paulownia or Basswood.
3. Choose 89mm for a balanced combination of light, view and contemporary style.
4. Choose 114mm for the clearest view and a bold finish on larger windows.

There is no need to make the decision from a small product photograph.

Test all four louvre sizes in the Shutters365 design tool, keep the window details the same and see the difference before you order.

Your completed design will also be checked by the Shutters365 team before it is made.