How to Measure a Wall for Panel Molding

Panel molding lives or dies on its margins. Frames that are a centimetre out at one end of a wall look wrong from across the room, even to people who could not tell you why. The good news is that getting it right is a measuring job, not a carpentry job, and there are only four numbers you actually need.

The four measurements that matter

1. Usable wall width. Corner to corner, measured at the height the frames will sit. Walls are rarely square, so take it at the top of the frame line and again at the bottom and use the smaller number.
2. Usable wall height. From the top of the baseboard to the underside of the ceiling or crown molding. Not floor to ceiling, the baseboard and crown are not part of the panel field.
3. Obstructions. The distance from the left corner to every outlet, switch, radiator bracket, doorway and window reveal. Write down both edges of each one.
4. Furniture line. The height of anything that will sit against the wall: a bed headboard, a console, a sofa back, a TV bracket. Frames that disappear behind furniture are wasted frames.

How to take them on your own

Hook the tape over the baseboard and let it run along the floor for the width; a tape will hold its own weight across a normal room. For the height, measure at three points, left, centre, right, because older ceilings drop. Use the shortest of the three so the top rail stays parallel to the ceiling rather than parallel to the floor. For a pre-cut MDF version, see the Board and Batten Wall Kit.

Write every number in millimetres or in eighths of an inch. Rounding to the nearest centimetre is where most layouts start going wrong, because the error multiplies across every gap.

Turning measurements into a layout

Once you have the numbers, the layout is arithmetic: total width, minus the outer margins, minus the width of every frame, divided by the number of gaps. Doing that by hand is where people give up, so we published a free wall molding calculator that does it for you. Enter width, height and the number of frames you want and it returns the frame sizes and the clear gaps between them.

For vertical battens rather than frames, the board and batten calculator does the same job for batten spacing. If you'd rather skip measuring and cutting, the Vertical Board and Batten Accent Wall Kit ships pre-cut and ready to prime.

Two mistakes that ruin a wall

Centering on the wall when the furniture is off-centre. If the bed sits 20 cm left of the wall's centre, a layout centred on the wall will look crooked even though it is mathematically perfect. Centre on the object people look at, and let the outer margins differ.

Making the outer margins smaller than the gaps. The margin between the end frame and the corner should be equal to or larger than the gaps between frames. Smaller margins make the wall look crowded and cheap. If the numbers force a narrow margin, drop one frame.

Which kit fits once you have the numbers

Take the frame count and the frame proportions the calculator gives you and match them to a layout. Three-over-three sets are the default for dining rooms, tall single-row frames suit bedrooms and hallways, and if you want the grid rather than the frame, look at board and batten or shaker paneling. The DIY Board and Batten Wall Panels delivers this style in paintable MDF, already cut to size.

Not sure the profile is right before you commit? Order the sample box and hold it against the wall at the height you plan to run it.

Want the numbers already worked out? See our measured layouts by wall size: ready-made frame sizes for 8, 10, 12, 14 and 16 ft walls, each with a drawing and cut list.