Baking Pan Size Converter Formula

Understand the math behind the baking pan size converter. Each variable explained with a worked example.

Use the Baking Pan Size Converter

Formulas Used

Original Pan Area

original_area = area1

New Pan Area

new_area = area2

Recipe Scale Factor

scale_factor = area2 / area1

Size Difference

percentage = ((area2 - area1) / area1) * 100

Variables

VariableDescriptionDefault
length1Original Pan Length(in)13
width1Original Pan Width(in)9
length2New Pan Length(in)8
width2New Pan Width(in)8
area1Original pan area= length1 * width1calculated
area2New pan area= length2 * width2calculated

How It Works

How to Convert Between Baking Pan Sizes

Formula

Scale Factor = New Pan Area / Original Pan Area

For rectangular pans: Area = Length x Width

Multiply each ingredient by the scale factor to adapt the recipe.

Example

Switching from a 13x9 pan (117 sq in) to an 8x8 pan (64 sq in) requires scaling to 64/117 = 0.55x the recipe.

Worked Example

Scale a recipe from a 13x9 inch pan to an 8x8 inch pan.

length1 = 13width1 = 9length2 = 8width2 = 8
  1. 01Original pan area: 13 x 9 = 117 sq in.
  2. 02New pan area: 8 x 8 = 64 sq in.
  3. 03Scale factor: 64 / 117 = 0.55.
  4. 04Use 55% of each ingredient amount.

Ready to run the numbers?

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