Baking Pan Size Calculator

Enter the length, width and shape of the pan the recipe calls for, and the same for the pan you have. For rectangles the area is length times width, and for rounds it is pi divided by 4 times the diameter squared. The multiplier is the new pan's area divided by the original.

Measure across the inside of the pan, from rim to rim, and keep the batter depth about the same.

Baking Pan Size: worked example

Original pan length (in)	13
Original pan width (in)	9
Original pan shape	Rectangle or square
New pan length (in)	8
New pan width (in)	8
New pan shape	Rectangle or square
Recipe multiplier for the new pan	0.55×
Original pan area (sq in)	117
New pan area (sq in)	64

Baking Pan Size: formula

Recipe multiplier = area of the new pan ÷ area of the original pan (rectangle: length × width; round: π ÷ 4 × diameter²)

NIST Handbook 44: Units and Systems of Measurement · Rectangle: Wolfram MathWorld · Circle: Wolfram MathWorld

Pan material and color change baking, since dark pans brown faster. Very deep or shallow batter changes the time and texture. Scaling by area assumes the same batter depth, which volume-based sizing achieves for tall pans.

Eggs are hard to divide, so a multiplier of 0.5 is easiest.

Common error: Matching pans by the number of inches on a side. A 9 inch round holds far less than a 9 inch square, so the shape changes the area even when the number is the same.

Baking Pan Size: changing Original pan length (in)

Original pan length (in)	Recipe multiplier for the new pan	Original pan area (sq in)	New pan area (sq in)
10	0.71×	90	64
12	0.59×	108	64
13 (example)	0.55×	117	64
14	0.51×	126	64
16	0.44×	144	64

Baking Pan Size: compare input ranges

Input	Tested from	To	Recipe multiplier for the new pan: low input	Recipe multiplier for the new pan: high input	Swing
New pan length (in)	7	9	0.48×	0.62×	0.14× (25%)
New pan width (in)	7	9	0.48×	0.62×	0.14× (25%)
New pan shape	Rectangle or square	Round	0.55×	0.43×	0.12× (21%)
Original pan shape	Rectangle or square	Round	0.55×	0.70×	0.15× (27%)
Original pan width (in)	8	10	0.62×	0.49×	0.12× (22%)
Original pan length (in)	12	14	0.59×	0.51×	0.08× (15%)

Baking Pan Size: individual input comparisons

Input	Value	Recipe multiplier for the new pan	Original pan area (sq in)	New pan area (sq in)
Original pan length (in)	10	0.71×	90	64
	12	0.59×	108	64
	13	0.55×	117	64
	14	0.51×	126	64
	16	0.44×	144	64
Original pan width (in)	7	0.70×	91	64
	8	0.62×	104	64
	9	0.55×	117	64
	10	0.49×	130	64
	11	0.45×	143	64
Original pan shape	Rectangle or square	0.55×	117	64
Original pan shape	Round	0.70×	91.9	64
New pan length (in)	6	0.41×	117	48
	7	0.48×	117	56
	8	0.55×	117	64
	9	0.62×	117	72
	10	0.68×	117	80
New pan width (in)	6	0.41×	117	48
	7	0.48×	117	56
	8	0.55×	117	64
	9	0.62×	117	72
	10	0.68×	117	80
New pan shape	Rectangle or square	0.55×	117	64
New pan shape	Round	0.43×	117	50.3

Baking Pan Size: combined input changes

Original pan length (in) / Original pan width (in)	7	9	11
10	0.91×	0.71×	0.58×
12	0.76×	0.59×	0.48×
13	0.70×	0.55×	0.45×
14	0.65×	0.51×	0.42×
16	0.57×	0.44×	0.36×

Baking Pan Size: which assumptions move the result?

Chart quantity	Displayed settings
New pan length (in)	6 → 10
Recipe multiplier for the new pan	0.41× → 0.68×
Original pan length (in)	13
Original pan width (in)	9
Original pan shape	Rectangle or square
New pan width (in)	8
New pan shape	Rectangle or square

Chart quantity	Displayed settings
New pan width (in)	6 → 10
Recipe multiplier for the new pan	0.41× → 0.68×
Original pan length (in)	13
Original pan width (in)	9
Original pan shape	Rectangle or square
New pan length (in)	8
New pan shape	Rectangle or square

Baking Pan Size: values and definitions

Quantity and definition	Value used
Original pan length (in) — For a round pan, enter the diameter.	13
Original pan width (in) — For a round pan, enter the diameter again.	9
Original pan shape — Sets how length and width become area.	Rectangle or square
New pan length (in) — For a round pan, enter the diameter.	8
New pan width (in) — For a round pan, enter the diameter again.	8
New pan shape — Sets how length and width become area.	Rectangle or square
Recipe multiplier for the new pan	0.55×
Original pan area (sq in)	117
New pan area (sq in)	64

Baking Pan Size: half and double New pan length (in)

New pan length (in)	Recipe multiplier for the new pan
4	0.27×
8	0.55×
16	1.09×

Cooking & Kitchen calculators: Coffee to Water Ratio Calculator, Recipe Cost Per Serving Calculator, Recipe Scaling Calculator.

A recipe is written for a certain batter depth, and the pan sets that depth. A 9 by 13 inch pan has 117 square inches of floor, and an 8 inch square pan has 64. Moving the batter from the big pan to the small one raises its depth by about 1.8 times unless you cut the recipe to roughly 55 percent, which the multiplier here gives directly.

Aim to keep the batter at the depth the recipe assumed, then watch the oven. A deeper batter needs a lower temperature or longer time.

Scale the ingredients on the recipe scaling calculator, cost the batch on the recipe cost per serving calculator and check brewing on the coffee ratio calculator. The circle area and rectangle area calculators show the geometry, and the fraction calculator helps split amounts.

Can I use a different pan size than the recipe says?

Yes, if you adjust the amount of batter to the pan's area and watch the baking time.

How much does a 9-inch round pan hold compared with 9 by 13?

The 9-inch round has about 64 square inches and the 9 by 13 has 117, so the round holds a little over half as much.

Does baking time change with the pan size?

It depends on batter depth. Same depth bakes about the same, while deeper batter takes longer.

Baking Pan Size Calculator