Cake pan calculator
This cake pan calculator compares the batter volume of an original and a new pan, then gives the recipe scaling factor. Multiply every ingredient by that factor to keep the same batter depth.
Round, square and rectangular pans are supported in centimetres or inches. For a useful comparison, enter the depth of batter you intend to pour rather than the full wall height.
Recipe scaling factor
×1.44
Multiply every ingredient by 1.44
More batter by 44%
Original pan volume
1,571 ml
6.64 US cups
New pan volume
2,262 ml
9.56 US cups
Formula
round: π × (d ÷ 2)² × h; rectangle: length × width × h; factor = new volume ÷ original volume
Current-value substitution
2,262 ml ÷ 1,571 ml ≈ 1.44
Enter the actual batter depth, not the full height of the pan wall.
Cake pan conversion formula
- Round pan: V = π × (diameter ÷ 2)² × batter depth.
- Square pan: V = side² × batter depth.
- Rectangular pan: V = length × width × batter depth.
- Recipe factor = new pan volume ÷ original pan volume.
- New ingredient amount = original amount × recipe factor.
Example: converting a 20 cm pan to 24 cm
For two round pans with equal batter depth, the factor is the ratio of squared diameters: 24² ÷ 20² = 1.44. That turns 300 g of flour into 432 g and 500 g of frosting into 720 g.
Without scaling the recipe, the layer in the 24 cm pan would be about 31% shallower. It may bake faster, so check the cake itself rather than relying only on the original timer.
Common pan volumes at 5 cm batter depth
| Pan | Calculated volume | Versus 20 cm round |
|---|---|---|
| 20 cm round | 1,571 ml | ×1.00 |
| 22 cm round | 1,901 ml | ×1.21 |
| 24 cm round | 2,262 ml | ×1.44 |
| 20 × 20 cm square | 2,000 ml | ×1.27 |
| 20 × 30 cm rectangle | 3,000 ml | ×1.91 |
Batter depth and baking time
- Keeping the same batter depth usually keeps baking time reasonably close, even when pan area changes.
- A deeper layer takes longer to heat through; a thinner layer bakes faster and can dry out.
- Do not fill a pan to the rim: most cakes need headroom to rise.
- For fractional eggs, beat an egg and weigh out the required share.
- Yeast, baking soda, baking powder and spices may not scale perfectly linearly; follow the needs of the specific recipe.
Frequently asked questions
How do I convert a recipe to a different pan diameter?
At equal batter depth, divide the square of the new diameter by the square of the old one. Moving from 20 to 24 cm gives a factor of 1.44.
How do I calculate the volume of a round cake pan?
Multiply π by the square of half the diameter and by batter depth: V = π × (d ÷ 2)² × h.
Should I enter the pan's full height?
No. For recipe scaling, enter batter depth. Filling the full wall volume would overstate the amount because a cake needs room to rise.
Can I convert a round pan to a rectangular pan?
Yes. The calculator finds each volume with the appropriate shape formula and divides the new volume by the original volume.
Will baking time change with pan size?
It should stay fairly close at equal batter depth. A deeper layer needs longer and a thinner layer finishes sooner, so begin checking early.
Updated: 2026-08-16