Kitchen Cornice and Pelmet Calculator
How much kitchen cornice and pelmet do you need? The usual method works each one out separately, but most cornice is sold for use as either, so the offcuts can be shared. Enter your runs of wall and tall units and get every piece, with the returns and mitres, cut from real lengths.
Last reviewed: 30 September 2026
Cornice
Enter each run as the length along its front: the unit widths added up. A return is the piece at an open end, back to the wall. Wall units get cornice and pelmet, tall units cornice only. Leave the extra allowance at 0%: the plan already counts every cut.
How Much Kitchen Cornice and Pelmet Do I Need?
DIY Kitchens' method is to add up the unit widths plus a nominal 400mm for each return, divide by the length and round up, once for the cornice and once for the pelmet. A 2400mm run of wall units open at both ends comes to 2 + 2 = 4 lengths of 2.6m that way. The cutting plan needs 3, because the Wickes and B&Q products are both sold for cornice or pelmet, so an offcut from one can make a piece of the other.
It works the other way too. When a run plus its mitre is just longer than one length, it needs a join and a whole extra length, which a sum spread across the runs does not see. In the table below the separate sums are over in 8 of 14 cases and short in 1.
How the Plan Works
- Cornice and pelmet. Cornice along the wall units, tall units and dressers; pelmet along the wall units only (DIY Kitchens).
- Returns. At each open end, a return back to the wall, 290mm by default from Howdens' planning drawing. Measure yours, and deeper for a tall unit.
- Mitres. Howdens: 45 degree mitres at corners, all mitre bonded. Each mitred end adds the profile depth, 25mm by default (our rule).
- Offcuts shared. Pieces packed into lengths longest first with a 3mm saw cut, cornice and pelmet together, no piece under 300mm (our working).
What it does not do: curved or angled units, cornice fittings, or light pelmets that need a different profile.
Cornice Lengths, With Sources
Both are sold for use as cornice or pelmet. Cornice has to match the kitchen range, so these are examples of each length.
| Length | Product page |
|---|---|
| 2400mm | GoodHome Alisma High gloss White Cornice & pelmet, (L)2400mm (H)35mm |
| 2600mm | Wickes Dakota White Matt Slab Contemporary Cornice, 2.6m (80 x 25mm, cornice or pelmet) |
The method and the 400mm return allowance are DIY Kitchens'. The mitre rule is from Howdens' guide to decor end panels and cornice/pelmets, and the 290mm wall cabinet depth from its planning dimensions. The mitre allowance, the packing and the saw cut are our own working.
Common Kitchens: Lengths Needed
Generated from the calculator above, with 290mm returns on wall units, 580mm on the tall unit, and nothing added. Each cell is the cutting plan, then DIY Kitchens' separate sums.
| Kitchen | 2400mm | 2600mm |
|---|---|---|
| One run, 2400mm, both ends open | 3 (4) | 3 (4) |
| One run, 1800mm, both ends open | 3 (4) | 2 (2) |
| Two runs of 1200mm either side of a hood | 4 (4) | 3 (4) |
| L, 2400 + 1500mm | 5 (4, short) | 4 (4) |
| L, 3000 + 1800mm | 5 (6) | 5 (6) |
| Wall run 2400mm + tall unit 600mm | 4 (4) | 3 (4) |
| U, 1200 + 2400 + 1200mm | 6 (6) | 5 (6) |
Frequently Asked Questions
How much kitchen cornice and pelmet do I need?
DIY Kitchens' method is to add up the unit widths plus a nominal 400mm for each return, divide by the length and round up, once for the cornice and once for the pelmet. But most cornice is sold for use as either, so offcuts from one can make pieces for the other. A 2400mm run of wall units open at both ends comes to 2 + 2 = 4 lengths of 2.6m by that method, and the cutting plan needs 3. In the table below the method is over in 8 of 14 cases and short in 1, when a run plus its mitre is just longer than one length.
How long is a return?
The piece that turns the corner at an open end and runs back to the wall. Howdens' planning drawing puts the front of a standard wall cabinet 290mm from the wall, so the calculator starts there. DIY Kitchens' 400mm is an ordering allowance, not a measurement. A tall unit's return is deeper, so measure it. Howdens says to leave a gap where the return meets the wall if you are tiling.
Do the corners need mitring?
Yes. Howdens: "Only use 45 degree mitre joints at corners" and "All corners must be mitre bonded". A mitre's long point runs past the corner by about the depth of the profile, so the calculator adds that to both pieces at each open end: 25mm by default, the depth of the Wickes cornice (our rule). Change it to suit yours.
Does pelmet go on tall units?
No. DIY Kitchens counts cornice along the wall units, tall units and dressers, and pelmet along the wall units only. Set each run to wall units or tall units, and the calculator leaves the pelmet off the tall ones.
Does the length matter?
Yes. For the default run, 2400mm lengths (B&Q) need 3 and 2600mm (Wickes) need 3. For an L of 2400 and 1500mm on 2400mm lengths, the 2400mm run plus its mitre is longer than one length, so it needs a join and 5 lengths, where DIY Kitchens' method gives 4. Cornice has to match the kitchen range, so choose the colour first.