About this tool

Baking Pan Size Converter

Scale any recipe between pan sizes with an exact ingredient multiplier, bake-time advice, and overflow warnings.

The Baking Pan Size Converter divides your pan's brim volume by the recipe pan's brim volume to give the exact multiplier for every ingredient, then adds bake-time advice and an overflow warning based on how deep the batter would sit. Round volumes come from pi x radius squared x depth, rectangles from length x width x depth, with bundt and cupcake tins using their real published capacities. It is for home bakers who own the wrong tin and want the recipe scaled properly instead of guessed.

How to use Baking Pan Size Converter

1. 1

   Open Baking Pan Size Converter on AltFTool — it loads instantly in your browser.

2. 2

   Choose what the recipe asks for under 'Recipe pan (what the recipe asks for)' and what you own under 'Your pan (what you will bake in)' — 12 presets from Round 6″ through Rectangle 9 × 13″ and Loaf 9 × 5″ to Bundt 10″ (12-cup) and a Cupcake tin (12 standard). Swap pans flips the two.

3. 3

   Read the headline 'Multiply every ingredient by ×N' and the Practical kitchen rounding beside it, which snaps to a real kitchen fraction from ½× to 3× or says 'Keep recipe as-is' when the difference is under 10%. Below it, Bake time & temperature gives the adjusted timing and a fill bar marked at ⅓ and ⅔ flags 'Overflow risk without scaling' or 'Layer would be very thin without scaling'.

4. 4

   Type any quantity into the Quick ingredient scaler to see its scaled amount, then press Copy for the full report or Download to save it as pan-conversion.txt.

Why use Baking Pan Size Converter

• Scales by volume, not by diameter

  It compares actual brim capacity, which is why a 9-inch square holds about 27 percent more batter than a 9-inch round even though both are called nine inches.

• Warns you before the batter goes over

  It works out what fraction of the new pan unscaled batter would fill and flags anything above the two-thirds line as an overflow risk or below one-third as too thin.

• Bake-time advice tied to batter depth

  The advice is driven by the computed depth ratio, so a deeper bake gets a 15 C (25 F) temperature drop and a 15 to 30 percent longer estimate rather than generic guidance.

Common use cases

• The recipe calls for a 9-inch round and all you own is a 9 x 13 rectangle — you need the multiplier before you start weighing flour.
• You want to turn a single layer cake batter into cupcakes and need to know roughly how many liners it fills and how much sooner to check them.
• You are halving a 9 x 13 traybake into an 8-inch square and want to know whether the shallower batter means pulling it out early.

Frequently asked questions