Pan Size Converter
Convert recipes between different pan sizes in inches or cm. Calculate ingredient adjustments when using square, rectangular, or round pans of different sizes.
Reviewed by the Calcura editorial team · Last reviewed
- Question
- How do I convert a recipe to a different pan size?
- Answer
- Calculate the area of both pans and divide: multiplier = new_pan_area ÷ original_pan_area. Multiply every ingredient by that number. A 9-inch round pan (63.6 in²) swapped to an 8-inch square (64 in²) is almost a 1:1 swap (1.01×); a 9×13 rectangle (117 in²) swapped to an 8-inch round (50.3 in²) is 0.43× — roughly half the recipe.
▸Show formula & caveatsHide formula & caveats
- Formula
multiplier = new_pan_area / original_pan_area (round: π × r²; rect: L × W)- Caveats
- Assumes similar batter depth. Going from a shallow sheet to a deep round pan changes bake time significantly.
- Bake time is not linear with size: expect +10-20% for a meaningfully larger pan, -10-20% for smaller. Start checking doneness early.
- For yeast-raised doughs and layered cakes, pan geometry changes rise and structure — scaling by area alone can give uneven results.
From Pan
To Pan
Common baking pan area reference
Baking surface area for standard US pans in square inches and square centimeters, with volume capacity at standard 2-inch depth.
| Pan | Area (in²) | Area (cm²) | Volume (cups) | Rough equivalent |
|---|---|---|---|---|
| 8-inch round | 50.3 | 324 | 6 | 8×8 square (×0.79) |
| 9-inch round | 63.6 | 410 | 8 | 8×8 square (×1.00) |
| 10-inch round | 78.5 | 506 | 10 | 9×9 square (×0.97) |
| 8×8 square | 64 | 413 | 8 | 9-inch round (×1.00) |
| 9×9 square | 81 | 523 | 10 | 10-inch round (×1.03) |
| 9×13 rectangle | 117 | 755 | 14–15 | Two 9-inch rounds |
| 11×7 rectangle | 77 | 497 | 9 | 9×9 square (×0.95) |
| 10×15 jelly roll | 150 | 968 | 18 | 1.5× a 9×13 |
| 12-cup muffin tin | 36 | 232 | 3 | One 6-inch round |
| 9-inch springform | 63.6 | 410 | 10 | 9-inch round (deeper) |
| 9×5 loaf | 45 | 290 | 8 | Half an 8-inch square |
| 10-inch tube (angel food) | 78.5 | 506 | 16 | Deep 10-inch round |
What This Calculator Does
Compares the horizontal area of two baking pans and returns a multiplier for scaling a recipe between them. Supports square, rectangular, and round pans in inches or centimeters, and converts across unit systems. Assumes batter depth should stay similar across the swap.
When To Use This Calculator
Halving a 9×13 sheet cake into an 8×8 square
117 sq in → 64 sq in gives a 0.55× multiplier. A 2-cup batter becomes 1.1 cups.
Swapping a European 28 cm round for a US 9-inch round
616 cm² vs 413 cm² — scale the recipe down to 67% for a 9-inch pan.
Baking in a round pan when the recipe calls for a square
A 9-inch round (63.6 sq in) substituted for a 9×9 square (81 sq in) needs 0.79× the batter — or expect a deeper bake.
Scaling a brownie recipe up for a half-sheet pan
8×8 (64 sq in) → 11×17 half-sheet (187 sq in) → 2.92× multiplier; expect a thinner finish and less baking time.
How It Works
Baked items rise vertically from a roughly fixed batter depth, so horizontal area is the right metric for scaling — not volume, which would double-count depth. For rectangular pans, area = length × width; for round pans, area = π × (d/2)². Unit conversion uses the exact 1959 international inch (1 in = 2.54 cm). The multiplier is simply the ratio of target area to source area, and every ingredient scales by that same factor to keep the recipe in ratio.
Formula
area_rect = L × W | area_round = π × (d/2)² | multiplier = area_new / area_originalReal-World Example
Scenario
A family brownie recipe is written for a 9×13 inch pan but you want to make a smaller batch in an 8×8 inch pan. The recipe uses 2 cups flour, 1.5 cups sugar, 4 eggs, ¾ cup cocoa, 1 cup butter.
Calculation
9×13 = 117 sq in. 8×8 = 64 sq in. Multiplier = 64 ÷ 117 = 0.547. Flour: 2 × 0.547 = 1.09 cups. Sugar: 1.5 × 0.547 = 0.82 cup. Eggs: 4 × 0.547 ≈ 2 eggs. Cocoa: 0.75 × 0.547 = 0.41 cup. Butter: 1 × 0.547 = 0.55 cup.
Result
1.09 cups flour, 0.82 cup sugar, 2 eggs, 0.41 cup cocoa, 0.55 cup butter — the 8×8 version of the brownie recipe.
Common Mistakes to Avoid
Mistake: Using volume (length × width × depth) instead of area
Solution: Batter depth should stay similar, not scale. Use floor area only. Volume scaling leads to under-filled pans and dried-out edges.
Mistake: Forgetting to adjust baking time
Solution: A smaller pan with thicker batter needs more time; a larger pan with thinner batter needs less. Start checking at 80% of the original time and use a toothpick test.
Mistake: Scaling leavening linearly for very large changes
Solution: Baking powder and soda don't scale perfectly past ~2× either direction. For jumps beyond that, search for a recipe written at the target scale.
Mistake: Treating 'half-sheet' and 'quarter-sheet' as interchangeable names
Solution: A US half-sheet is 13×18 in (234 sq in); a commercial half-sheet is 18×26 in (468 sq in). Measure your actual pan and enter the dimensions.
Related cooking tools
When This Isn't the Right Tool
Loaf pans where shape matters more than area
Use instead: Loaves rise and crust differently based on depth-to-width ratio. Use a loaf-specific recipe rather than area scaling.
Tube or bundt pans
Use instead: These have a central hole that changes effective area and heat distribution. Area math under-predicts batter capacity by ~15%.
Pie, tart, and springform pans with sloped sides
Use instead: Sloped walls mean the top area and bottom area differ. Use the pan's labeled capacity (cups or liters) rather than floor area.
How to Verify This Calculation
Cross-check by computing π × r² manually for a round pan. A 9-inch round: π × (4.5)² = 63.6 sq in. If the tool reports anything materially different, the radius-vs-diameter input is wrong (the field asks for diameter).
Sources
- NIST Handbook 44 — linear measurement standards — Exact inch-to-centimeter relationship (1 in = 2.54 cm) used by this tool.
- BIPM — SI Brochure — International definitions of metric length.
- King Arthur Baking — pan substitutions guide — Reference for standard US pan sizes and substitution guidance.
- USDA FSIS — doneness temperature references — Use internal temperature, not time, when pan size changes alter bake times.
Reviewed by the Calcura editorial team · Last reviewed