Enter the pan your recipe calls for and the pan you have — get an exact time adjustment in seconds.
Open full calculator →Every guide includes a size comparison table, time adjustments, and answers to the questions real bakers actually ask.
The 8×8 is 79% the area of a 9×9. That difference matters for brownies and cakes but less so for bars. Here's exactly what to change.
Read guide → Pan substitutionTwo 8×8 pans are actually 9% more area than one 9×13. Great for potlucks — but there are a few things to know before you split the batter.
Read guide → Reference chartEvery common pan size in one place: area in square inches, volume in cups, closest substitutes, and best uses. Bookmark this one.
View chart → Shape conversionA 9" round and an 8×8 square are nearly identical in area (63.6 vs 64 sq in). See the full conversion table for every diameter.
Read guide →Most blogs give you a rule of thumb. PanSwap gives you the math.
Both pans drawn side by side at the same scale so you can immediately see how different the size really is.
Uses the baking industry standard: adjusted time = original × scale factor^0.7 — not a rough percentage.
Brownies, layer cakes, quick breads, and cheesecakes each respond differently to pan changes. PanSwap adjusts the notes accordingly.
Every swap gets a confidence score — Safe, Works with adjustments, or Significant changes needed — so you know what you're getting into.
Mix and match rectangular, square, and round pans freely. The calculator handles the area math regardless of shape combination.
For large size differences, the calculator flags when to lower the oven temperature and explains why.