King Arthur & Joy of Baking Geometry Standard
9x9 Square Pan to 9x13 Pan Converter
Area-based volume scaling for round, square, loaf, Bundt, and 9x13 sheet pans.
Interactive Pan Area Comparator
Pan Geometry & Oven Science Guide
A 9x9 square pan has an area of 81 sq inches, while a 9x13 rectangular pan has an area of 117 sq inches. A 9x13 pan is 44.4% larger than a 9x9 square pan.
To scale a 9x9 square bar or cake recipe to a 9x13 pan, multiply all ingredients by 1.45x (or increase by 50%). If unscaled, layers will be about 30% thinner.
Standard Cake Pan Surface Area & Volume Guide
Surface area dictates batter depth, while volume dictates maximum safe capacity.
| Pan Name & Dimensions | Surface Area | Batter Capacity | Ratio vs 8" Round |
|---|---|---|---|
| 6-inch Round (2" deep) | 28 sq in | 4 cups | 0.56x |
| 8-inch Round (2" deep) | 50 sq in | 6 cups | 1.00x (baseline) |
| 9-inch Round (2" deep) | 64 sq in | 8 cups | 1.27x |
| 10-inch Round (2" deep) | 79 sq in | 10-11 cups | 1.57x |
| 8x8-inch Square (2" deep) | 64 sq in | 8 cups | 1.27x (matches 9" round) |
| 9x9-inch Square (2" deep) | 81 sq in | 10 cups | 1.61x |
| 9x13-inch Rectangle | 117 sq in | 14-15 cups | 2.33x (matches two 9" rounds) |
| 8.5x4.5-inch Loaf Pan | 38 sq in | 6 cups | 0.76x |
| 9x5-inch Loaf Pan | 45 sq in | 8 cups | 0.90x |
| 10-inch Bundt Pan | 78 sq in | 12 cups | 1.55x |
| 9-inch Springform Pan | 64 sq in | 10 cups (3" deep) | 1.27x |
Pan Substitution Rules & Baking Physics
Scaling Factor
Multiply recipe by 1.45x (or 1.5x) to move from 9x9 to 9x13.
Area Comparison
81 sq inches (9x9) vs 117 sq inches (9x13).
Bake Time Adjustment
If unscaled, reduce baking time by 5 to 7 minutes.
Frequently Asked Questions
How do I scale a 9x9 pan recipe to a 9x13 pan?
Multiply the recipe ingredients by 1.45 (or 1.5x) for equivalent layer thickness.
Can I double a 9x9 recipe for a 9x13 pan?
Doubling makes the batter too thick (2.0x vs 1.44x needed). A 1.5x multiplier is much closer to ideal depth.
How much more batter does a 9x13 hold than a 9x9?
A 9x13 pan holds 14-15 cups of volume, compared to 10 cups for a 9x9 pan.
Related Pan Conversions
Baking & Kitchen Cluster Cross-Links
Verified ingredient weight conversions and pan geometry calculators across our baking suite:
Butter Sticks Converter 113.4g per stick
Yeast Packet Converter 7g = 2 1/4 tsp
Cake Pan Size Converter Area & volume
250g Butter to Sticks 2.2 sticks (block)
7g Yeast to Teaspoons 2 1/4 tsp
8" to 9" Cake Pan 1.27x factor
9x13 Pan to Round Two 9" rounds
1 Stick Butter in Grams 1/2 cup / 8 tbsp
Instant vs Active Dry 1.25x ratio
9" Round to 8" Square Exact 1:1 match