What size cake do I need?
Put in the guest count and get every option at once: one tin, tiers, a traybake or cupcakes, each with what it really feeds.
Free. No signup needed.The short answer
Thirty guests at a birthday takes one 12 inch round, which cuts into 40 party slices, or a 9 by 13 traybake at 36. A hundred at a wedding takes a 12 by 18 half sheet at 108 slices, or three tiers of 12, 10 and 8 inch at 118. A party slice is about 1.5 by 2 inches and a wedding slice is 1 by 2, which is why the same tin feeds twice as many at a wedding. Put your number in and the calculator gives you every format side by side.
What size cake do I need?
BakerInbox
Who you are feeding
How it is being served
Handed round on a napkin. Birthdays, christenings, office cakes.
Bake this
One 12 in round cake
Feeds 40, which is 10 spare
Portions needed
30
One each, and nobody goes back for seconds
Every way to feed 30
One 12 in round cake
40 portions, 10 spare
The simplest thing to make, the cheapest to deliver, and it still looks like a proper cake.
The catch. A tin this wide is heavy and awkward to bake evenly. Check the bake time before you commit.
How much batter that tin takes2 tiers: 8 in, 6 in
32 portions, 2 spare
Height and presence, and each tier can be a different flavour so there is something for everyone.
The catch. Dowels, boards and a lot more work. It has to be stacked at the venue, not in the car.
Plan the tiers and price themOne 9 x 13 in traybake
36 portions, 6 spare
Cuts into 6 by 6 even party slices. Fastest to make, easiest to transport, and nothing to stack.
The catch. It does not look like a celebration cake, so it wants a top tier or a board of cupcakes beside it.
Work out the cutting grid33 cupcakes
33 portions, 3 spare
No cutting, no plates, no knife at the venue, and everyone gets the same amount.
The catch. There is no moment where somebody cuts the cake, and a lot of cases to fill.
Buttercream for that manyA party slice is about 1.5 by 2 inches and roughly an inch and a half of cake on a napkin. A wedding slice is half that, which is why the same tin feeds twice as many at a wedding as it does at a birthday. Counts come from the published trade serving charts, interpolated for the sizes between the rows. Order one size up if there are children who will want seconds, or if anyone is taking a slice home.
Size settled. BakerInbox turns it into a quote, then an order, then a date in your calendar.
Start free trialCake size by guest count
| Guests | One round tier | Tiered | Traybake |
|---|---|---|---|
| 10 | 6 in | 6 infeeds 12 | 8 x 8 in square |
| 15 | 7 in | 8 infeeds 20 | 8 x 8 in square |
| 20 | 8 in | 8 infeeds 20 | 8 x 8 in square |
| 25 | 10 in | 8, 6 infeeds 32 | 9 x 13 in |
| 30 | 12 in | 8, 6 infeeds 32 | 9 x 13 in |
| 40 | 12 in | 10, 8 infeeds 48 | 12 x 18 in |
| 50 | 14 in | 10, 8 infeeds 48 | 12 x 18 in |
| 75 | More than one tier | 12, 10, 8 infeeds 88 | 16 x 24 in |
| 100 | More than one tier | 12, 10, 8 infeeds 88 | 16 x 24 in |
| 150 | More than one tier | 14, 12, 10, 8 infeeds 142 | 18 x 26 in |
Cut into party slices. Handed round on a napkin. Birthdays, christenings, office cakes.
Cut into wedding slices
| Guests | One round tier | Tiered | Traybake |
|---|---|---|---|
| 10 | 6 in | 6 infeeds 12 | 8 x 8 in square |
| 15 | 7 in | 8 infeeds 24 | 8 x 8 in square |
| 20 | 8 in | 8 infeeds 24 | 8 x 8 in square |
| 25 | 9 in | 8, 6 infeeds 36 | 8 x 8 in square |
| 30 | 10 in | 8, 6 infeeds 36 | 8 x 8 in square |
| 40 | 12 in | 10, 8 infeeds 62 | 9 x 13 in |
| 50 | 12 in | 10, 8 infeeds 62 | 9 x 13 in |
| 75 | 14 in | 12, 10, 8 infeeds 118 | 12 x 18 in |
| 100 | More than one tier | 12, 10, 8 infeeds 118 | 12 x 18 in |
| 150 | More than one tier | 14, 12, 10, 8 infeeds 196 | 16 x 24 in |
Cut into wedding slices. The formal finger portion. Half the size, twice the people.
Cut into dessert plates
| Guests | One round tier | Tiered | Traybake |
|---|---|---|---|
| 10 | 8 in | 6 infeeds 7 | 9 x 9 in square |
| 15 | 9 in | 8 infeeds 13 | 9 x 13 in |
| 20 | 12 in | 8 infeeds 13 | 12 x 18 in |
| 25 | 12 in | 8, 6 infeeds 21 | 12 x 18 in |
| 30 | 14 in | 8, 6 infeeds 21 | 12 x 18 in |
| 40 | More than one tier | 10, 8 infeeds 31 | 16 x 24 in |
| 50 | More than one tier | 10, 8 infeeds 31 | 16 x 24 in |
| 75 | More than one tier | 12, 10, 8 infeeds 58 | 18 x 26 in |
| 100 | More than one tier | 12, 10, 8 infeeds 58 | Two trays |
| 150 | More than one tier | 14, 12, 10, 8 infeeds 93 | Two trays |
Cut into dessert plates. Sat down, with a fork, often with cream. The most generous cut.
Made with BakerInbox. Free cake tools at bakerinbox.com/tools
Picking the format
Start from the number of people, not from a tin. What moves the answer most is how the cake is being eaten, and after that how much work you want on the day.
Slice size
The slice decides the size before the tin does
A party slice is about 1.5 by 2 inches, handed round on a napkin. A wedding slice is 1 by 2, half the width, which is why the same tin feeds twice as many at a wedding. An 8 inch round gives 20 party slices, 24 wedding slices and about 13 plated dessert portions. Get that one choice wrong and every number after it is wrong. If you already know the tin and only want the count, the how many servings in an 8 inch cake chart works it the other way round.
One tin
Most parties want a cake, not a tower
Thirty people is a birthday, not a wedding, and the honest answer is usually one tin. A 12 inch round cuts into 40 party slices, so it covers thirty with ten spare and it still looks like a proper cake. Cheapest to bake, easiest to deliver, and nothing to stack at the venue. The catch is one flavour and a wide, heavy tin that bakes slowly, so check how much batter a 12 inch tin takes before you mix.
Tiers
Tiers buy height, not portions
Two tiers of 8 and 6 inch give 32 party slices, which is fewer than one 12 inch tin and far more work. You stack a cake for presence and for a second flavour, not to feed more people. Past about seventy five guests tiers start to earn it, since a single tin that wide will not bake evenly. Three tiers of 12, 10 and 8 inch give 118 wedding slices, and how many a wedding cake serves takes that stack all the way to a price.
Traybakes
What caterers quietly use for a crowd
A traybake, a sheet cake in the US, is the format nobody suggests and the one that keeps winning. A 9 by 13, the quarter sheet, gives 36 party slices. A 12 by 18 half sheet gives 72, or 108 cut into wedding fingers. It bakes flat, travels flat, and needs no dowels or boards. It does not look like a celebration cake, so put a small round on top or a board of cupcakes beside it. The how many portions a 9 by 13 traybake gives tool prints the cutting grid, not just the total.
Cupcakes
Under forty people they often win
One each plus about ten percent, so thirty guests takes 33 cupcakes. No knife at the venue, no plates, no arguing over who got the corner piece, and everyone gets the same amount. What you lose is the moment somebody cuts the cake, which for a birthday can be the whole point. A small round sat on a cupcake board gives you both.
FAQ
Common questions
What size cake do I need for 30 guests?
One 12 inch round, which cuts into 40 party slices and leaves ten spare. A 10 inch gives only 28, so it comes up short. If you would rather not bake a tin that wide, a 9 by 13 traybake gives 36, or 33 cupcakes covers thirty with a couple over.
How much cake do I need for 100 guests?
A 12 by 18 half sheet cut into 1 by 2 inch wedding slices gives 108, which covers a hundred on its own. Three tiers of 12, 10 and 8 inch give 118 wedding slices. At bigger party slices those same tiers give only 88, so step up to a 16 by 24 tray at 128, or keep the tiers and cut a plain kitchen cake in the back.
What size cake will feed 150 people?
An 18 by 26 full sheet gives 156 party slices, which is the simplest answer at this number. Four tiers of 14, 12, 10 and 8 inch give 196 wedding slices, or 142 party slices, so at party size that stack lands eight short on its own. Most bakers do a tiered cake for the photographs and a traybake cut out of sight.
How big a sheet cake do I need for 50 people?
A 12 by 18 half sheet. Cut into the American 2 inch squares it gives 54, and cut into 1.5 by 2 inch party slices it gives 72. A 9 by 13 quarter sheet will not do it: that tray gives 24 squares or 36 party slices. One 14 inch round also covers 50 at 54 party slices.
Will a quarter sheet cake feed 25?
Only just, and it depends how you cut it. A 9 by 13 gives 24 two inch squares, one short of 25, and 36 at the smaller 1.5 by 2 inch party slice. Handed round on napkins it is fine. As a plated dessert it is not, because the same tray gives 18.
How many people does an 8 inch cake feed?
Twenty at a party, cut 1.5 by 2 inches. Twenty four at a wedding, cut 1 by 2. About 13 as a sat down dessert portion with cream. For the sizes either side, a 6 inch gives 12 party slices, a 10 inch gives 28 and a 12 inch gives 40.
What size cake for 20 guests?
An 8 inch round gives exactly 20 party slices, which is no margin at all. Go to a 9 inch for 24 and you have four spare for seconds and for the slice that hits the floor. A 9 by 9 square traybake also gives 24 and is quicker to cut.
Do I need a tiered cake, or will one tin do?
One tin, up to about 50 people. A 14 inch round gives 54 party slices and a 12 by 18 tray gives 72, both without a single dowel. Tiers are for height, for a second flavour, or for a guest count no single tin can reach and still bake evenly.
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