What is cake-pan-size-converter?

An alias for this pan area scaling tool.

Can I combine two round layers into a sheet?

Compare total batter volume to the sheet pan area; this tool compares one pan footprint to another.

Baking Pan Conversion Calculator

Swap cake pan sizes without guessing how much batter fits.

King Arthur defaults

US cup standard

Clear assumptions

Compares pan floor areas and returns a batter multiplier = toArea ÷ fromArea (optional depth ratio).

Limitation: Educational kitchen conversion only.

Jump to calculator · Sources & review

Original pan shapeOriginal diameter (in)For round pans.Original length (in)For square/rectangular pans.Original width (in)New pan shapeNew diameter (in)New length (in)New width (in)Depth ratio (optional)Multiply area factor by depth change. Default 1 = same depth.

How to Convert Pan Sizes

Enter original and new pan dimensions. Round pans use diameter; rectangles use length × width.

Set the original pan shape and dimensions.

Weigh when it matters

Volume-to-weight charts are averages. For finicky baking, weigh on a kitchen scale.

What the Batter Multiplier Means

It is the ratio of pan floor areas (with optional depth adjustment). A 9-inch round holds about 26.6% more batter than an 8-inch round.

Worked Examples

8-inch → 9-inch round

Inputs

fromShape:round

fromDiameterIn:8

toShape:round

toDiameterIn:9

depthRatio:1

Result

×1.2656 batter

Area scales as r²: (4.5²)/(4²) = 1.265625.

9×13 → 9×9 square

Inputs

fromShape:rectangular

fromLengthIn:9

fromWidthIn:13

toShape:square

toLengthIn:9

toWidthIn:9

depthRatio:1

Result

×0.6923 batter

81 sq in ÷ 117 sq in ≈ 0.6923.

Check your cup style

US customary cups differ from metric cups (250 mL). This cluster uses the US legal cup.

Frequently Asked Questions

Yes. Deeper or shallower batter changes timing even when area scaling is correct.

Still have questions about this calculation?

Try the Calculator

Pan Area Formulas

Geometry-only model; oven time still depends on batter depth and recipe type.

Formula

area = π × (diameter ÷ 2)²

Round

area = π × (diameter ÷ 2)²

Rectangle

area = length × width

Scientific Background

Assumptions follow published kitchen references cited in sources. Results are rounded for display.

Sources & review

Baking Pan Conversion Calculator documents the references behind its formulas and assumptions. Always treat results as educational estimates, not personalized professional advice.

Last reviewed

July 22, 2026

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