How to scale a recipe
To resize a recipe, divide the desired number of servings by the original number of servings. The result is the recipe scaling factor.
Multiply every ingredient amount by that same factor.
Example: scale 4 servings to 6
A recipe that originally makes 4 servings and needs to make 6 servings has a scale factor of 1.5.
If the original recipe uses 2 cups of flour, the scaled quantity is 3 cups.
If it uses 1 1/2 cups of sugar, the scaled quantity is 2 1/4 cups.
Scaling recipes up
When the desired servings are greater than the original servings, the scale factor is greater than 1. Every ingredient quantity increases.
For example, changing 8 servings to 20 servings gives a scale factor of 2.5.
Scaling recipes down
When the desired servings are smaller than the original servings, the scale factor is less than 1.
For example, reducing a recipe from 8 servings to 2 servings uses a scale factor of 0.25, so each ingredient becomes one-quarter of its original amount.
Fractions and mixed fractions
Recipe quantities are often written as fractions rather than decimals. This calculator accepts standard fraction forms including:
1/2, 1/3, 2/3, 1/4, 3/4, 1 1/2 and 2 3/4.
Common Unicode kitchen fractions such as ½, ⅓, ⅔, ¼, ¾, ⅛, ⅜, ⅝ and ⅞ are also understood.
Practical kitchen fractions
The calculator always keeps the mathematical scaled quantity. When a result is very close to a common kitchen fraction, it also shows a practical fraction such as 1/2, 2/3, 3/4 or 1 1/4.
This is especially useful for cups, tablespoons and teaspoons, where fractions are often easier to measure than long decimals.
Ingredient units are preserved
Recipe scaling is different from measurement conversion. If an ingredient is entered in grams, the scaled result stays in grams. If it is entered in cups, the result stays in cups.
This avoids silently converting ingredients between volume and weight, which can be inaccurate without knowing the ingredient density.
Eggs and other whole items
Some ingredients do not divide conveniently. Scaling may produce a result such as 1.5 eggs.
For recipes where precision matters, one option is to beat the egg and use the required proportion by weight or volume. For casual cooking, practical rounding may sometimes be acceptable depending on the recipe.
Scaling baking recipes
The arithmetic for scaling a baking recipe is the same, but the cooking process may not scale perfectly. Pan size, batter depth, oven loading, mixing time and baking time can change when a recipe becomes much larger or smaller.
For sensitive baking recipes, use the scaled ingredient amounts as a starting point and follow any recipe-specific instructions for pan size and baking time.
Scaling seasoning and leavening
Mathematical scaling gives the proportional amount for salt, spices, baking powder, baking soda and yeast. In practice, very large recipe changes may require culinary adjustment rather than strict linear scaling.
Taste-sensitive seasonings can be added gradually when appropriate.
Scaling factor vs. percentage
A factor of 1.5 means the new recipe is 150% of the original recipe size. A factor of 0.5 means the new recipe is 50% of the original.
For general percentage changes, use the Percentage Calculator.
Recipe ratios
Recipe scaling preserves the ratio between ingredients. When every ingredient is multiplied by the same scale factor, their proportional relationship remains the same.
To work directly with ratios, use the Ratio Calculator.
Volume calculations
If you need to calculate the capacity of a container rather than scale recipe ingredients, use the Volume Calculator.
This calculator performs proportional ingredient scaling. Cooking times, oven temperatures, pan sizes, fermentation, seasoning and other preparation decisions may not change in the same proportion.
Frequently asked questions
How do I double a recipe?
Set the desired servings to twice the original servings. The scale factor becomes 2, and every ingredient amount is doubled.
How do I cut a recipe in half?
Set the desired servings to half the original servings. The scale factor becomes 0.5.
Can I enter fractions?
Yes. Values such as 1/2, 3/4 and 1 1/2 are supported, along with decimals.
Does the calculator convert cups to grams?
No. It preserves the unit entered for each ingredient because converting between volume and weight depends on the ingredient.
Does cooking time scale by the same factor?
Not necessarily. Ingredient quantities scale proportionally, but cooking time and other preparation conditions can change differently.
Using this calculator effectively
The Recipe Scaling Calculator adjusts an entire ingredient list when the number of servings changes. It supports decimal amounts, ordinary fractions, mixed fractions and common Unicode kitchen fractions.
Common uses
- Increasing a family recipe for a larger group while keeping every ingredient in proportion.
- Reducing a recipe to make fewer servings without manually recalculating each ingredient.
- Converting proportional results into practical kitchen fractions when the scaled value is close to a common fraction.
Tips for a better estimate
- Enter the recipe's actual original serving count and the number of servings you want to make.
- Keep each ingredient in its original measurement unit unless you intentionally perform a separate unit conversion.
- Remember that cooking time, pan size, fermentation, seasoning and other preparation details may not scale linearly with ingredient quantities.