Am I glad I ran onto this information on the Joy of Baking site (www.joyofbaking.com)! Pan sizes and the amount of batter they hold have always been a mystery to me. Well, Joy solved this mystery. If you’ve had trouble estimating batter amounts for pan sizes, you’ll appreciate this explanation as well.

To start with, different size pans hold different capacities (volumes) of batters, and this must be taken into account when substituting one pan size for another in a recipe. For instance, if you use a larger pan than asked for in a recipe this will change the depth of the batter (shallower) and therefore the batter will bake much more quickly. Likewise, if you use a smaller pan than asked for in a recipe this will also change the depth of the batter (deeper) and therefore the batter will take longer to bake.

And of course, the looks of the finished product will be drastically altered as well.

While I knew this stuff from trial and error, what’s confused me is how to know what size my baking dishes are (I have several without size indicators on their bottoms). My two glass rounds measure 9” across from outside to outside, but they measure 8” across from inside to inside. So which measurement do I go by? Well, Joy says “To determine the pan's dimensions always measure inside edge to inside edge of the pan so that you do not include the thickness of the pan in your measurement.” Hah! Mystery solved—I now know I have two 8” rounds.

And to measure the depth, place your ruler straight up from the bottom of the pan (do not slant the ruler). 

To determine the pan's volume (how much batter it will hold), pour pre-measured water by the cupful until the pan is filled to the brim.

Once you have measured the pan's dimensions and volume you can check the table below for pan substitutions. The ideal pan substitution is one that keeps the same batter depth as in the original recipe, by keeping the same pan area. In this way you do not have to make any drastic changes in baking times and temperatures. For example: you could substitute a 8 x 8 inch square pan (which is 64 square inches), for a 9 inch round pan (which is 63.5 square inches), without changing the baking time or oven temperature stated in the original recipe.

If the new pan makes the batter shallower than in the original recipe, this will cause the heat to reach the center of the pan more quickly and you will have more evaporation. To solve this problem you need to shorten the baking time and raise the temperature of the oven slightly. Correspondingly, if the new pan makes the batter deeper than in the original recipe, this will cause less evaporation and the batter will take longer to cook. To solve this problem you need to lengthen the baking time and lower the temperature of the oven slightly. This will keep the batter from over-browning.

Pan Conversion Formula: (Volume of the Pan Size you want to use) divided by (Volume of the Pan Size given in the recipe)

And one last piece of advice from Joy: Keep in mind that most home ovens will only accommodate up to a 17 x 14 inch (43 x 36 cm) pan. Watch out for this, because many baking sheets are 18 x 13 inches. So measure before you buy!

I’ll close with abundant appreciation to the Joy of Baking for this very needed instruction, and with the aforementioned pan substitution table. (This information is going straight into my Cook’n Chapter, “Baking and Cooking HOW-TOs!”)

Estimated Pan Size (inches)	Estimated Volume (cups)
ROUND
6 x 2 inches	4 cups
8 x 1 1/2 inches	4 cups
8 x 2 inches	6 cups
9 x 1 1/2 inches	6 cups
9 x 2 inches	8  cups
10 x 2 inches	11 cups
SPRINGFORM
9 x 2 1/2 inches	10 cups
9 x 3 inches	12 cups
10 x 2 1/2 inches	12 cups
BUNDT
7 1/2 x 3 inches	6 cups
9 x 3 inches	9 cups
10 x 3 1/2 inches	12 cups
TUBE
8 x 3 inches	9 cups
9 x 3 inches	12 cups
10 x 4 inches	16 cups
SQUARE
8 x 8 x 1 1/2 in.	6 cups
8 x 8 x 2 inches	8 cups
9 x 9 x 1 1/2 in.	8 cups
9 x 9 x 2 inches	10 cups
10 x 10 x 2 inches	12 cups
RECTANGULAR
11 x 7 x 2 inches	6 cups
13 x 9 x 2 inches	14 cups
JELLY ROLL
10 1/2 x 15 1/2 x 1	10 cups
12 1/2 x 17 1/2 x 1	12 cups
LOAF
8 x 4 x 2 1/2 in.	4 cups
8 1/2x4 1/2x2 1/2	6 cups
9 x 5 x 3 inches	8 cups
MUFFIN
1 3/4 x 3/4 in.	1/8 cup
2 3/4 x 1 1/8 in.	1/4 cup
2 3/4 x 1 1/2 in.	1/2 cup
3 x 1 1/4 inches	5/8 cup
Heart Shaped
8 x 2 1/2 inches	8 cups