Cake box sizing guide: footprint, depth and windows
Size a cake box to the cake board, not the cake: the box footprint should be the board size plus about a quarter inch, and the board should be about 2 inches wider than the cake. For depth, measure from the board to the tallest decoration and add 1 inch. An 8 inch round on a 10 inch board goes in a 10 by 10 by 5 inch box; a tall 10 inch cake on a 12 inch board goes in a 12 by 12 by 6.
Footprint: start from the board
The board is what the box holds, so the box is built around it. A standard board drops in with about a quarter inch to spare, enough to lift it out without tipping, not enough for it to slide. The board itself should give the cake about an inch of margin on every side, so frosting and piped borders never touch the walls.
| Round cake | Board | Box inside size | Typical depth |
|---|---|---|---|
| 6 inch | 8 inch | 8 x 8 in | 4 to 5 in |
| 8 inch | 10 inch | 10 x 10 in | 5 in |
| 10 inch | 12 inch | 12 x 12 in | 5 to 6 in |
| 12 inch | 14 inch | 14 x 14 in | 6 in |
| 14 inch | 16 inch | 16 x 16 in | 6 to 8 in |
Square and rectangular cakes follow the same rule: board 2 inches bigger each way, box a quarter inch bigger than the board. A 9 by 13 inch quarter sheet on an 11 by 15 board needs an 11 by 15 box. Our cake box runs any size from 6 by 6 by 3 to 16 by 16 by 8 inches, so a half sheet fits; a full sheet does not, and for that you want a corrugated box.
Depth: measure the tallest point, add 1 inch
Depth is where most boxes go wrong. Measure from the bottom of the board to the highest point of the finished cake: the piped rosette, the fruit, the topper. Add 1 inch so the lid never touches it, then round up to the next depth.
- 3 to 4 inches. Single layers, cheesecakes, tarts, brownies and bars.
- 5 inches. A two-layer cake with frosting and a modest border, the most common cake box.
- 6 inches. Three layers, naked cakes, or piped decoration on the top edge.
- 8 inches. Toppers, tall fondant work and stacked designs. On 20pt board, 8 inches is about as tall as the walls stay square on a full-size cake.
A tiered cake taller than 8 inches is a different job. We move to 24pt board or a corrugated base with a paperboard sleeve, and the cake should be delivered by hand, not shipped.
Loading: top lid or front opening
The standard cake box has lock corners and a tuck-in lid, so you lower the cake in from above. For decorated cakes, the front-loading style is safer: the lid hinges back and the front panel folds down, so you slide the cake in on its board. Same board, same lead time. If your team has ever dented a buttercream border lowering a cake into a box, choose the front-loading version.
The board the box is made from
Our cake box is 20pt SBS, virgin fiber and food-contact grade, with the inside left unprinted and food-contact documentation supplied with the quote. Ink and coating sit on the outside only. 20pt keeps the walls square under a full-size cake; the lighter 18pt we use for the bakery box with a window suits pastries and cookies.
Paperboard and cold do not mix well for long. A box that spends a day or two in the fridge is fine; one that sits there for several days absorbs condensation and softens. If cakes are stored boxed in the cooler, tell us at the quote stage.
Windows
A clear PET window in the lid sells a decorated cake, and it can be any shape that can be die cut. Keep it under about 60 percent of the lid area and leave at least half an inch of board around it, because the lid is what keeps the walls square when the box is carried. On a 14 inch box we usually suggest a window no wider than about 9 inches.
Cupcakes and slices
Cupcakes need an insert, not a bigger box. Our cupcake box with insert holds each cupcake by its liner in 2.25 inch holes, in 1, 2, 4, 6 and 12 counts; most buttercream swirls fit a 4 inch deep box. For a single portion, cake slice boxes are sized to hold one slice upright with clearance for the frosting.
Questions people ask
What size cake box do I need for an 8 inch round cake?
Put the cake on a 10 inch board and use a 10 by 10 inch box. A two-layer cake with frosting usually needs 5 inches of depth; measure the tallest decoration and add 1 inch to be sure.
How deep should a cake box be?
Measure from the bottom of the board to the highest point of the cake, add 1 inch, and round up. Two-layer cakes usually land at 5 inches, three layers or tall borders at 6, and toppers at 8.
Should the box match the cake or the board?
The board. The box is sized so a standard board drops in with about a quarter inch to spare. The board, in turn, is about 2 inches wider than the cake so nothing touches the walls.
Cake box or bakery box with a window: which do I need?
Use a cake box for whole cakes and anything taller than about 5 inches or heavier than about 3 pounds, since it is built on stiffer 20pt board. Use a bakery box with a window for pastries, cookies and small items under about 4 inches tall. Our bakery boxes guide covers grease resistance and those smaller sizes.
Is the board safe for food contact?
Yes. Our cake box is virgin fiber SBS, food-contact grade, with the inside unprinted. Food-contact documentation is supplied with the quote.
Can cake boxes go in the refrigerator?
For a day or two, yes. Over several days the board absorbs condensation and softens. If your cakes are stored boxed in the cooler, tell us at the quote stage.