Use this quick-reference to match your cake base to the right box every time. All sizes are nominal diameter/side length in inches.
Round Cake Boards
Size
Type
Thickness
Fits White Box
Fits Tall Box
4"
Single Board
~3 mm
✓ 6"+ box
—
5"
Single Board
~3 mm
✓ 6"+ box
—
6"
Single Board / Masonite 5mm
3 mm / 5 mm
✓ 6" box
—
6"
Double Board
~6 mm
✓ 7"+ box
—
7"
Single Board
~3 mm
✓ 7" box
—
8"
Single Board / Masonite 5mm
3 mm / 5 mm
✓ 8" box
—
8"
Double Board
~6 mm
✓ 9"+ box
—
9"
Single Board
~3 mm
✓ 9" box
—
10"
Single Board / Masonite 5mm
3 mm / 5 mm
✓ 10" box
✓ 10×10×10"
10"
Double Board
~6 mm
✓ 11"+ box
✓ 10×10×10" (snug)
11"
Single Board
~3 mm
✓ 11" box
—
12"
Single Board / Masonite 5mm
3 mm / 5 mm
✓ 12" box
✓ 12×12×12"
12"
Double Board
~6 mm
✓ 13"+ box
✓ 12×12×12" (snug)
ℹ️ A "snug" fit means the board slides in flush — suitable for flat-topped or single-tier cakes. Add one size up for decorated cakes needing side clearance.
Square Cake Boards
Size
Type
Thickness
Fits White Box
Fits Tall Box
4"
Single Board / Double Board
3 mm / ~6 mm
✓ 6"+ box
—
5"
Single Board
~3 mm
✓ 6"+ box
—
6"
Single Board / Masonite 5mm / Double Board
3–6 mm
✓ 6" box
—
7"
Single Board
~3 mm
✓ 7" box
—
8"
Single Board / Masonite 5mm / Double Board
3–6 mm
✓ 8" box
—
9"
Single Board
~3 mm
✓ 9" box
—
10"
Single Board / Masonite 5mm / Double Board
3–6 mm
✓ 10" box
✓ 10×10×10"
11"
Single Board
~3 mm
✓ 11" box
—
12"
Single Board / Masonite 5mm / Double Board
3–6 mm
✓ 12" box
✓ 12×12×12"
Round & Square Cake Drums
Size
Shape
Thickness
Fits White Box
Recommended Use
5"–7"
Round & Square
~12 mm
✓ Same-size box (standard white)
Small celebration cakes, individual tiers
8"–9"
Round & Square
~12 mm
✓ Same-size box
Single-tier, heavy cakes needing rigid support
10"–12"
Round & Square
~12 mm
✓ Same-size box / Tall box
Multi-tier base, display boards, transport
13"–16"
Round & Square
~12 mm
✗ Larger than standard box range
Display/presentation; wrap or use open box
18"
Round & Square
~12 mm
✗ Display only
Large tiered cakes, displays
10"–14"
Masonite Round (White/Gold/Black)
~5 mm
✓ Same-size box
Lighter than drum; premium finish for gifting
ℹ️ Drums are ~12 mm thick (vs ~3–6 mm for boards). Always check the box internal height allows for drum + cake + any decoration clearance. Add 25–50 mm clearance above the tallest decoration for transport.
Rectangle Boards & Drums
Size
Type
Box Compatibility
8×4"
Rectangle Board
Use a 9" or 10" white box, or cut-down custom box
10×4"
Rectangle Board
Use a 11"+ white box
15×6"
Rectangle Board
Oversize — use bespoke or open display box
16×8"
Rectangle Board
Oversize — use bespoke or open display box
16×12"
Rectangle Drum
Oversize — presentation/display use
18×14"
Rectangle Drum
Oversize — presentation/display use
Frequently Asked Questions
Board vs drum — which should I use?
Boards (3–6 mm) are lightweight and ideal for single-tier cakes being collected in person, or where the cake sits inside a box for support. Drums (~12 mm) add rigidity and height, making them the better choice for heavy multi-tier cakes, postal or courier delivery, or when the board doubles as a presentation base at the table. A drum also prevents the cake from sinking on a soft surface.
How much clearance do I need inside the box?
Allow at least 25 mm (1") between the top of any decoration or stacked tier and the lid. For fondant-covered cakes with tall decorations or toppers, size up to a Tall Box (10×10×10", 12×12×12", or 14×14×12") to avoid the lid pressing on your finish.
Can I use a square drum in a round box?
No — the corners of a square drum will protrude past the circular base of a round box, preventing the lid from closing. Always match the board/drum shape to the box shape, or use a square box for a square board.
My cake board is the same size as the box — will it fit?
Same-size pairings (e.g. 10" board in a 10" box) work for thin single boards (3–5 mm). Double boards and drums may be fractionally wider due to manufacturing tolerances — size up one inch to be safe, especially for decorated cakes where the icing extends to the board edge.
What box size should I use for a drum?
Match the box size to the drum size (e.g. 12" drum → 12" white box or 12×12×12" tall box). Remember the drum's 12 mm height counts toward total box depth, so factor that in alongside your cake height and decoration clearance.
Can I use Corner Extensions to make a box fit a larger board?
Yes — our Cake Box Corner Extensions (set of 4) raise the lid height of a standard white box, giving extra clearance for tall decorations on the existing base. They do not increase the footprint of the box, so the board size must still match or be smaller than the box base.
Dimensions are nominal/industry-standard. Minor manufacturing tolerances may apply. Always test-fit before delivery.