How much to charge for a 6 inch cake
A two-layer 6 inch chocolate-frosted birthday cake has $7.95 of ingredients in this example. With a board and box, an hour of work at an example $15 an hour and 10% overhead it costs $27.45 to make, and at a 40% margin it sells for $45.75. Cut into the 12 slices Wilton lists, that is $3.81 a slice. Decorating is extra, and has its own section below. The prices are examples, so put in your own.
The 8 inch cake, as the recipe lists it
King Arthur's Classic Birthday Cake is "one 8” or 9” two-layer cake" with chocolate frosting. The page lists 1 hour of hands-on time, 26 to 42 minutes of baking and 3 hours in total. The example uses its amounts for the cake and the frosting; the optional almond extract and the 74 g of hot water in the frosting are left out. Flour, sugar, eggs, butter and milk use September 2026 averages from the Bureau of Labor Statistics. Cocoa, confectioners' sugar, vanilla, oil, salt and baking powder carry a star: those are my own placeholder prices, so check them against what you pay. The board and box ($2.50) are a placeholder too.
| Ingredient | Used | Package | Cost |
|---|---|---|---|
| All-purpose flour | 240 | $0.55 / 1 | $0.29 |
| Table salt | 1.25 | $1.29 / 26 * | $0.01 |
| Baking powder | 2 | $2.49 / 8.1 * | $0.09 |
| Large eggs | 4 | $2.27 / 1 | $0.76 |
| Granulated sugar | 397 | $1.02 / 1 | $0.89 |
| Vanilla extract (cake) | 14 | $5.99 / 2 * | $1.50 |
| Whole milk | 227 | $4.11 / 1 | $0.26 |
| Butter (cake) | 57 | $3.96 / 1 | $0.50 |
| Vegetable oil | 67 | $4.49 / 48 * | $0.25 |
| Natural cocoa powder | 106 | $4.99 / 8 * | $2.33 |
| Confectioners' sugar | 454 | $2.49 / 2 * | $1.25 |
| Table salt (frosting) | 0.25 | $1.29 / 26 * | $0.00 |
| Vanilla extract (frosting) | 14 | $5.99 / 2 * | $1.50 |
| Butter (frosting) | 284 | $3.96 / 1 | $2.48 |
| Ingredients for the batch | $12.10 | ||
The 8 inch cake costs $32.56 to make and sells for $54.27 at a 40% margin. Open the 8 inch cake in the calculator to change any line.
Scaling it down to 6 inches
King Arthur gives one recipe for 8 or 9 inches and none for 6, so the 6 inch version here is my arithmetic. A round pan's area grows with the square of its width, so a 6 inch pan holds 6 x 6 = 36 where an 8 inch pan holds 8 x 8 = 64. The cake amounts are multiplied by 36/64, which is 0.5625; the frosting is handled separately, see below. That gives, for example, 2.25 eggs, which you can't crack. Round to whole eggs in the kitchen and expect the cost to move by a few cents.
Sanity check against a second source: Wilton's serving guide lists 2 1/4 cups of batter per 2 inch layer for a 6 inch pan and 4 cups for an 8 inch pan. 2 1/4 divided by 4 is 0.5625, the same ratio. Wilton's figures for 2 inch pans "are based on a two-layer, 4 in. high cake".
Labor stays at the recipe's 60 minutes of hands-on time in the example, because the page states one hands-on time for the recipe, whatever the pan size. Change it to your own timing. Open the 6 inch cake in the calculator.
| Line | 6 inch | 8 inch |
|---|---|---|
| Ingredients | $7.95 | $12.10 |
| Board and box (placeholder) | $2.00 | $2.50 |
| Labor, 60 min at $15 (example) | $15.00 | $15.00 |
| Overhead, 10% | $2.50 | $2.96 |
| Cost to make | $27.45 | $32.56 |
| Price at a 40% margin | $45.75 | $54.27 |
Price per slice
Wilton's chart gives party and wedding serving counts per size. It says: "For the purposes of this chart, party serving amounts are based on cake slices that measure about 1½ x 2 inches in size." It also warns: "Remember that number of servings are intended as a guide only. Actual results may vary." Wilton lists 12 servings for a 6 inch cake in both columns, so the two per-slice prices match. The prices below are the whole-cake prices from the table above, divided by those counts.
| Size | Cake price | Party slices | Per party slice | Wedding slices | Per wedding slice |
|---|---|---|---|---|---|
| 6 in | $45.75 | 12 | $3.81 | 12 | $3.81 |
| 8 in | $54.27 | 20 | $2.71 | 24 | $2.26 |
Wilton also lists the icing for a cake that is iced and decorated: about 2 1/2 cups for 6 inches and 3 1/2 cups for 8. King Arthur's frosting recipe is the same for both. Scaling it by pan area would give 56%, but Wilton's icing figures give 2.5 / 3.5, so the frosting rows here use 71% of the 8 inch amounts. That ratio is my arithmetic from Wilton's numbers. If you sell by the slice, add a plate or clamshell to each slice and count the slice you cut but can't sell.
Decoration time
I am treating the recipe's hands-on hour as mixing, baking and frosting. Piping, sprinkles, a drip or a name on top is a separate job, so give it its own minutes. The decoration times below are examples I picked, valued at the same example $15 an hour, and each is added to the labor line before overhead and margin. They are not from King Arthur or Wilton.
| Decoration time | Decoration labor | Cost to make | Cake price | Per slice (12) |
|---|---|---|---|---|
| None | $0.00 | $27.45 | $45.75 | $3.81 |
| 30 min | $7.50 | $35.70 | $59.50 | $4.96 |
| 60 min | $15.00 | $43.95 | $73.25 | $6.10 |
| 120 min | $30.00 | $60.45 | $100.75 | $8.40 |
The lowest price by margin
Take the 6 inch cake with 30 minutes of decoration (cost $35.70). A 0% margin is the break-even price: below it you pay to bake. Each higher margin is the share of the price you keep after costs.
| Margin | Matching markup | Cake price | Per slice (12) | Kept per cake |
|---|---|---|---|---|
| 0% (break-even) | 0% | $35.70 | $2.98 | $0.00 |
| 20% | 25% | $44.62 | $3.72 | $8.92 |
| 30% | 42.9% | $51.00 | $4.25 | $15.30 |
| 40% | 66.7% | $59.50 | $4.96 | $23.80 |
| 50% | 100% | $71.40 | $5.95 | $35.70 |
Whether to charge more than break-even is your call, and so is the margin. Cottage food rules decide whether and how you may sell cakes, so check your state's before you take orders. For the difference between margin and markup, see markup vs margin for bakers.
Your own cake
Open the 6 inch or 8 inch cake in the calculator, then change the prices, the board and box, your minutes and your margin. For the same cake as 28 cupcakes with frosting costed separately, see cupcake cost per unit. A sheet pan cut into pieces is on the brownies page.