Baking Pan Size Converter

Frequently Asked Questions

• How do I convert a recipe to a different pan size?+
  Work out the base area of the pan the recipe was written for and of the pan you want to use, then divide the new area by the original. Multiply every ingredient by that factor and the batter stands as deep in your pan as it did in the recipe’s. The calculator does the arithmetic, so a factor of 1.27, for example, means 27% more of everything.
• Why base area and not the pan’s width or volume?+
  Batter spreads across the bottom of the pan, so the amount needed to reach a given depth depends on the base area, which grows with the square of the width. Keeping the depth the same is what keeps the bake similar: Joy of Baking calls the ideal substitution one that keeps the same batter depth by keeping the same pan area. Volume, the pan’s capacity, answers a different question: whether that batter fits.
• How do I know whether the batter will fit?+
  Enter both pans’ depths. The calculator then shows each pan’s straight-sided capacity to the brim and how far up your pan the scaled batter will sit. A 9 × 3 inch springform recipe moved into a 9 × 2 inch round has the same base area, so the factor is 1.00, but the batter sits one and a half times as high up the shallower pan: a springform filled halfway becomes a round filled three-quarters. Fill ceilings vary by source: King Arthur and Baker Gatherer say no more than two-thirds, Wilton says half to two-thirds and only half for 3 inch deep pans, and Nigella says roughly half way.
• How is the area of each pan calculated?+
  A round pan’s area is π times the radius squared, where the radius is half the diameter you enter. A square pan’s area is its side times itself, and a rectangular pan’s is its length times its width. Measure inside edge to inside edge, as Joy of Baking advises, and hold the ruler straight up for the depth.
• Can I convert between a round and a square pan?+
  Yes. A square has 4 ÷ π, about 27%, more base than a round of the same width, which is why UK and Australian charts step down about one size: olive magazine pairs a 20 cm round with an 18 cm square and a 23 cm round with a 20 cm square. The calculator gives the exact factor for any pair you enter.
• Can the two pans be in different units?+
  Yes. Each pan has its own unit, so a recipe written for a 9 inch round can be compared with an 18 cm square. Switching a pan’s unit converts the numbers already typed (1 inch = 2.54 cm). Areas are shown in each pan’s own unit, and the factor is worked out in square centimetres so the units cancel.
• Do I change the oven temperature too?+
  The sources we read disagree, and the calculator does not choose for you. Joy of Baking says to raise the temperature slightly and shorten the time for a shallower batter, and lower it slightly and lengthen the time for a deeper one. Baker Gatherer goes the other way for a batter spread thinner: drop it by 10°C and start checking 10 minutes early. olive magazine says to keep it the same when moving from a round to a square tin. Wilton bakes its largest pans at 325°F rather than 350°F. King Arthur gives no temperature change and suggests checking 10 to 15 minutes early in a larger pan.
• Does this work for loaf, bundt and tube pans?+
  For loaf pans, enter the inside length, width and depth as a rectangle and compare capacities rather than relying on area alone. Bundt and tube pans are not shapes the calculator models; measure each one by filling it with water to the brim and compare the amounts, which also catches sloped sides.
• Will scaling change the texture?+
  Scaling keeps the ingredient ratios identical, so the batter is the same; what changes is the bake when the depth in the pan changes. For a big change in depth, a pan closer in proportion, or splitting the batter across two pans, keeps you nearer the recipe.
• Is the Baking Pan Converter free?+
  Completely free, with no account or usage limit. It runs entirely in your browser, collects no data, and works offline once the page has loaded.