A Roman blind can make a window feel beautifully finished, but the effect depends on proportion. Roman blind measuring is where a considered scheme becomes a truly tailored one: a few millimetres can influence how neatly the blind sits, how much light it controls and how balanced the room feels.

Unlike a ready-made dressing, a bespoke Roman blind is designed around your individual window, fabric and interior. Whether you are softening a formal sitting room, adding warmth to a bedroom or bringing a refined finish to a kitchen-diner, taking accurate dimensions is the first step towards an elegant result.

Roman blind measuring begins with where the blind will sit

Before reaching for the tape measure, decide whether the blind will sit inside the recess or outside it. This choice affects not only the dimensions, but the character of the finished window.

A recess-fitted Roman blind sits within the window opening. It is a clean, understated option that shows off attractive frames and mouldings, and it can suit rooms where shutters, curtains or architectural details already provide visual interest. It is particularly effective where the recess is deep enough to accommodate the blind without catching on handles or vents.

An exact-fit blind outside the recess is mounted to the wall, ceiling or face of the frame. This approach can make a modest window appear larger and offers stronger coverage at the sides, which is useful in bedrooms and rooms where privacy matters. It also provides a practical solution where a recess is shallow, uneven or interrupted by a protruding handle.

There is no universally right choice. A recessed blind often feels more discreet; an outside-recess blind can look more generous and decorative. Consider the window in the context of the whole room, including curtain poles, radiators, furniture placement and the amount of fabric you would like to see when the blind is raised.

Measuring a recess for a Roman blind

For a blind fitted within a recess, use a rigid metal tape measure rather than a fabric tape. Measure the width in three places: at the top, centre and bottom of the opening. Old properties, particularly those with characterful original windows, are rarely perfectly square. Record the narrowest width, as this is the dimension the blind must fit within.

Next, measure the drop in three places: left, centre and right. Use the shortest measurement. Measure from the top inside edge of the recess to the sill, or to the point at which you would like the blind to finish if there is no sill.

It is tempting to make your own allowance for clearance. However, made-to-measure suppliers commonly apply their own fitting deduction for recess blinds. In most cases, provide the exact recess dimensions requested and allow the maker to calculate the final blind size. Deducting twice can leave unwanted gaps at the sides and undermine the tailored appearance you are aiming for.

Check the depth, not just the width and drop

A Roman blind has fabric and a headrail, so recess depth matters. Measure from the front edge of the recess to the nearest obstruction, such as a handle, tile, vent or secondary glazing. If handles project into the space, a recess fit may be impractical or may need to sit forward of them.

Also look above the window. The headrail must be fixed securely, with enough clear space for the blind to operate. Deep recesses can be ideal, but only if the blind will clear the window furniture as it rises and falls.

How to measure outside the recess

For an outside-recess fit, you are choosing the finished coverage rather than measuring an opening the blind must sit inside. Start by deciding how far beyond each side of the window you would like the fabric to extend. A projection of around 50 to 100 mm on either side is often attractive, though a wider overlap may be preferable for greater privacy or improved light control.

Measure the total width across this chosen area, rather than the width of the glass alone. Check that the proposed blind will not conflict with a wall light, picture rail, alcove shelving or curtain treatment. In a compact room, even a small adjustment can make the composition feel more considered.

For the drop, measure from the desired fixing point to the bottom edge of the blind. A wall-mounted Roman blind may finish at the sill, below the sill or lower still, depending on the proportions of the room. In many interiors, a blind that extends slightly below the sill gives a more luxurious, intentional finish and reduces light escaping beneath it.

Where possible, mount the blind high enough that, when raised, the stacked fabric does not obscure too much glass. This is especially worthwhile in Edinburgh and the Lothians, where making the most of natural daylight can transform a room during the darker months.

Allow for the fabric stack

Roman blinds do not disappear completely when lifted. The folds gather at the top, creating a fabric stack that varies according to the blind’s drop, fabric weight and lining. A light linen may form a relatively compact stack, while a richly textured velvet or interlined fabric will need more visual space.

This detail matters when a window has a transom, a low ceiling, fitted cabinetry or a beautiful view you do not want to interrupt. Discuss the likely stack height before confirming the fixing position, particularly for wide blinds or designs in heavier, insulating fabrics.

Pattern placement deserves equal care. Large-scale florals, stripes and statement prints can look exquisite in a Roman blind, but their repeat affects the way the fabric is cut and positioned. If a motif needs centring, the finished blind may be planned around the design rather than purely around the fabric’s usable width. This is one of the advantages of choosing a bespoke treatment: the practical measurements and decorative details are considered together.

Small details that change the result

Before ordering, measure each window individually, even where they appear identical. Differences in plasterwork, sills and frame dimensions are common, and a room looks more polished when every blind is made for its own opening.

Take note of anything that may affect operation or fitting. This includes:

• projecting handles, locks and trickle vents
• tiled reveals or uneven plasterwork
• radiators directly beneath the window
• curtain poles, pelmets or nearby wall lights
• child safety requirements for chain-operated blinds

If fitting to a wall or ceiling, identify a sound fixing surface. Plasterboard may require appropriate fixings, while concrete lintels and steel supports may influence where brackets can be positioned. A beautiful blind should feel effortless in use, and that begins with a secure, well-planned installation.

When a professional measure is worthwhile

Confident homeowners can successfully measure straightforward windows, particularly for an outside-recess blind on a clear wall. Yet a professional survey brings reassurance when windows are unusually shaped, recesses are uneven, several treatments need to work together or the chosen fabric is a significant investment.

It is also valuable when combining Roman blinds with curtains or plantation shutters. The spacing between layers needs careful planning so that each element operates freely and the finished look remains graceful rather than crowded. A professional can assess the sightlines, stack position, bracket placement and proportions in the room itself.

For homeowners seeking a more considered approach, Harvey Bruce can help bring measurements, fabric choices and wider interior styling into one coherent scheme. Seeing swatches alongside paint colours, flooring and furnishings often makes the final decision feel far more certain.

A final check before your blind is made

Write each measurement clearly, label it by room and window, and state whether it is a recess size or the desired finished blind size. Check the figures once more against the window itself, not from memory or a photograph. If the supplier asks for exact recess measurements, do not add deductions unless specifically instructed.

The most beautiful Roman blinds are not simply the right size. They are positioned with care, made in a fabric that belongs in the room and fitted to enhance the light, architecture and everyday comfort of the home. Taking a little extra time at the measuring stage gives that craftsmanship the space to shine.