THE METHOD, MADE CLEAR
The same recipe.
A different batch.
Batchscale multiplies your original ingredient quantities by one scale factor. You choose that factor through a serving count or a comparison of pan areas.
Scaling by servings
The factor is target servings divided by original servings. A recipe for four scaled to six has a factor of 6 ÷ 4 = 1.5. Each quantity is multiplied by 1.5; the ingredient’s unit stays exactly as you entered it.
Scale factor = target servings ÷ original servings
New ingredient amount = original amount × scale factor
A four-serving recipe for six
200 g flour becomes 300 g. 100 g butter becomes 150 g. Two eggs become three eggs. An ingredient entered as 1/3 cup becomes 1/2 cup because one third multiplied by one and a half is one half.
The calculator does not redefine a serving’s size. If the original portions are small, the scaled portions retain that assumption.
Scaling by pan area
For a straight-sided rectangular pan, base area is inside length multiplied by inside width. For a circular pan, base area is π multiplied by the square of the radius, or π × diameter² ÷ 4. Each area is multiplied by the number of matching pans. The factor is target total area divided by original total area.
Rectangle area = length × width
Circle area = π × diameter² ÷ 4
Pan factor = target total base area ÷ original total base area
This comparison assumes you want the same filled depth. Measure the usable inside dimensions, and use the same unit for both sets of pans. You may select centimetres or inches, but the unit applies to every pan measurement in the plan.
One 20 cm square pan to one 24 cm round pan
The square has an area of 20 × 20 = 400 cm². The round pan has an area of π × 24² ÷ 4 ≈ 452.389 cm². The factor is approximately 1.130973. An original 200 g of flour becomes approximately 226.195 g.
This is not a 24 ÷ 20 = 1.2 scaling problem: area depends on two dimensions, and the shapes also differ.
Several pans and split batches
Moving from one 20 cm round pan to two identical 20 cm round pans doubles the total area, so the factor is 2. Moving from two such pans to one halves it. Each original-pan count and each target-pan count must be a whole number. If one side contains several different pan sizes, calculate the combined area yourself or make separate plans; a single side of this tool represents matching pans only.
Area scaling is unsuitable for changing batter depth, comparing very tapered pans, ring pans or pans with a central tube, or treating a muffin tray as a solid rectangle. It also does not determine a safe fill height or account for expansion. Use the recipe’s instructions and the actual equipment.
Decimals, fractions and mixed numbers
Ingredient quantities accept positive decimal numbers such as 0.5, simple fractions such as 3/4, and mixed numbers such as 1 1/2. Common fraction characters, including ½ and ⅓, are also accepted. Use a decimal point rather than a comma. A zero denominator, negative amount, empty quantity or text such as “to taste” is rejected so a stale result is not mistaken for a new plan.
The result shows a simple exact fraction when the computed amount matches one with a denominator of 2, 3, 4, 6, 8, 12 or 16 within numerical precision. Other results stay decimal: the tool does not silently turn 1.13 into 1 1/8. Displayed decimal values are rounded for readability; CSV export preserves the underlying number.
Halving 1½ cups
The original amount is 1.5 cups. A factor of 0.5 gives 0.75 cups, shown as 3/4 cups. If the original amount is 3/4 cup and the factor is 2/3, the result is 1/2 cup.
Why units stay unchanged
A cup of flour and a cup of oil do not share one universal weight. Cup and tablespoon definitions can also differ by region. Batchscale therefore scales the number without converting volume to mass or choosing a cup standard. If you enter grams, you get grams. If you enter cups, you get cups using the same meaning as your original recipe. Use a verified ingredient-specific conversion separately if one is needed.
Eggs, leavening and seasoning
A calculated 1.5 eggs is an ingredient amount, not an instruction to cut an egg in half. One practical approach is to beat the egg and measure an appropriate fraction by weight, following the recipe’s method. The tool does not assume one egg’s weight or size. Salt, spices and leavening are multiplied arithmetically too; assess the original recipe and batch size before deciding whether that is appropriate.
Baking time does not scale linearly
Multiplying a recipe by 1.5 does not mean multiplying baking time by 1.5. Depth, pan material, oven loading and heat transfer affect doneness. The tool intentionally provides no scaled cooking time or temperature. Use the original recipe’s doneness cues, check the adapted batch appropriately, and follow relevant food preparation guidance.
Keeping the result
Copy recipe produces a readable list. CSV download records original and scaled quantities, units and the scale factor. Text beginning with spreadsheet formula characters is neutralised in the CSV export. Both actions happen in your browser, and the recipe is not submitted to the site operator.