DecoMoldings

inspiration · Arched

F&B Ammonite Arched Wall Molding

F&B Ammonite Arched Wall Molding: wall elevation, color data (LRV 69), living room layout for 12, 15, 18 ft walls, cut list, calculator and pre-cut kits.

Catalog snapshot View 2 sources ↓

Project calculator

Wall molding linear-foot estimate

Estimate for rectangular molding frames.

Estimated quantity122.28 linear feet

Divide by 7.87 ft (240 cm stick) and round up for the number of sticks.

Formula & assumptionsframe_count * 2 * (frame_width_inches + frame_height_inches) / 12 * (1 + waste_percent / 100)

Assumes identical rectangular frames. The waste allowance is editable. The estimate does not optimize cuts or include separate rails, baseboards, or other trim.

Overview

F&B Ammonite is a light gray with a warm (yellow) undertone and a calculated LRV of 69. Against white trim the contrast ratio is 1.28:1, which gives almost no contrast, so the molding reads through shadow alone (a tone-on-tone look); painted tone-on-tone, the arched pattern shows only through its shadow lines.

Arched layout on a 15 ft living room wall

Molding over the full wall height, upper and lower rows divided by a chair rail. On a 15 ft wall with an 8 ft ceiling this gives 5 frames per row, each 31.2 in wide, with 50 in upper and 21 in lower frames. The layout uses about 40.43 m of 2.5 cm molding, or 17 sticks of 240 cm, including 10% waste. Center the layout on the sofa or TV rather than the wall when furniture is off-center.

Building the arched pattern

Arched tops are pre-formed in MDF; the straight sides and the bottom rail are cut to the same width as the arch. Fix the arch first, then hang the sides from it.

Painting molding in F&B Ammonite

Grays sit in the middle of the contrast range: white trim reads clearly, while same-color trim gives a quiet, architectural look.

Wall elevation

F&B Ammonite wall, tone-on-tone trim, arched layout on a 15 ft wall. Colors are screen approximations.

Color data

ColorBrandCodeHexCalculated LRVUndertoneDepthContrast vs white trimContrast vs black trim
F&B AmmoniteFarrow & Ball#DDD8CF69warm (yellow)light1.28:111.61:1

Trim color pairings

PairingTrim colorHexContrastEffect
tone-on-toneF&B Ammonite#DDD8CF1:1Trim painted the same color as the wall
matching whiteSW Greek Villa#F0ECE21.2:1White with the closest undertone
contrastBlack#1F1F1F11.61:1Dark trim for a graphic outline

Living Room wall sizes: arched accent wall layout

Wall widthFrames per rowFrame widthFrame height (upper / lower)Molding incl. 10% waste240 cm sticksChair rail pieces (300 cm)
12 ft431 in50 / 21 in32.26 m142
15 ft531.2 in50 / 21 in40.43 m172
18 ft631.3 in50 / 21 in48.6 m212

Cut list for a 15 ft wall

Planning cut list
PieceQuantityLength
Frame top and bottom (lower row)1031.2 in
Frame sides (lower row)1021 in
Arch frame sides (upper row)1034.4 in
Arch top + bottom rail (upper row)531.2 in span
Chair rail2300 cm lengths

Pre-cut kits for this wall

Pre-cut kits that fit this project. Open a kit for photos, options and pricing.

Double Arched Wall Molding Set | Pre-Cut MDF Decorative Wall Panels01 / KIT

Double Arched Wall Molding Set | Pre-Cut MDF Decorative Wall Panels

From $133.60

View kit
Arched Decorative Wall Molding Panels, 1 to 5 Arches | Pre-Cut MDF02 / KIT

Arched Decorative Wall Molding Panels, 1 to 5 Arches | Pre-Cut MDF

From $146.40

View kit
Flexible Arch Trim Wall Molding Kit | Pre-Cut MDF Decorative Wall Panels03 / KIT

Flexible Arch Trim Wall Molding Kit | Pre-Cut MDF Decorative Wall Panels

From $83.40

View kit
Flexible Arched Wall Molding, Paintable MDF Wall Trim, Pre-Cut Arch Decorative Wall Panels | Picture Frame Molding, Accent Wall Trim04 / KIT

Flexible Arched Wall Molding, Paintable MDF Wall Trim, Pre-Cut Arch Decorative Wall Panels | Picture Frame Molding, Accent Wall Trim

From $73.60

View kit
Modern Arched Wall Panel Kit: Pre-Cut MDF Wall Molding05 / KIT

Modern Arched Wall Panel Kit: Pre-Cut MDF Wall Molding

From $140.00

View kit
Half Wall Arched Wainscoting Panels Kit | Pre-Cut MDF Easy Installation06 / KIT

Half Wall Arched Wainscoting Panels Kit | Pre-Cut MDF Easy Installation

From $73.60

View kit

Questions

How much molding do I need for a 15 ft living room wall with arched frames?

About 40.43 m (133 linear ft) including a chair rail and 10% waste, which is 17 sticks of 240 cm. That assumes 5 frames per row, 31.2 in wide, on an 8 ft ceiling.

Is F&B Ammonite warm or cool?

F&B Ammonite has a warm (yellow) undertone and reads as a light gray. Its calculated LRV is 69, so it reflects a lot of light and keeps molding shadows soft.

Should trim be the same color as F&B Ammonite walls?

Painting the molding the same color gives a modern, tone-on-tone finish where only shadows show the pattern. White trim adds almost no contrast, so the molding reads through shadow alone (a tone-on-tone look) (1.28:1), and black trim gives 11.61:1.

How high should the chair rail be in a living room?

About one third of the ceiling height: 32 in on an 8 ft ceiling, 36 in on 9 ft and 40 in on 10 ft. Center the layout on the sofa or TV rather than the wall when furniture is off-center.

Trace the details

Sources & dates

Prices, options and photos come from our product catalog on the date shown. Layout tables are planning estimates; measure your wall before ordering.

  1. Paint color dataset (screen approximations; LRV calculated)Recorded November 11, 2026
  2. DecoMoldings product catalogRecorded November 11, 2026