About the Recipe Scaler
This recipe scaler resizes a whole ingredient list at once. Paste the ingredients one per line, enter how many servings the recipe makes and how many you need, and every quantity is multiplied by the same factor — 1 1/2 cups becomes 2 1/4 cups when you scale 4 servings up to 6. Lines without a number, such as “pinch of salt” or “oil for frying”, are left untouched.
It is built for home cooks doubling a recipe for guests, halving a family recipe for two, and anyone batch-cooking or meal-prepping. It understands whole numbers, decimals, fractions like 3/4, mixed numbers like 1 1/2, Unicode fractions like ½ and ranges like 2–3. Cup and spoon measures are rounded to familiar kitchen fractions, while grams, millilitres and ounces are shown as decimals.
Scaling is linear, which works for most ingredients. Seasoning, leavening, cooking time and pan size do not always scale perfectly: taste as you go, and when you change the pan, use the pan size converter to keep batter depth right.
How to use the recipe scaler
- 1Enter how many servings the original recipe makes.
- 2Enter how many servings you want to make.
- 3Paste the ingredient list with one ingredient per line.
- 4Copy the scaled list, then check seasoning and pan size before cooking.
Formula and method
The scaler divides the servings you need by the servings the recipe makes to get one scaling factor, then multiplies every numeric quantity by it. Mixed numbers, fractions and Unicode fractions are converted to decimals first, and ranges such as 2–3 are scaled at both ends.
Results for cups, spoons and counts are rounded to the nearest common kitchen fraction (eighths, thirds or quarters) when within 0.02, otherwise shown to two decimals. Weights and metric volumes (g, kg, ml, l, oz, lb) are kept as decimals because they are measured on a scale or jug.
- f
- Scaling factor
- S₀
- Servings the original recipe makes
- S₁
- Servings you want
Worked examples
Scale a 4-serving batter to 6 servings
Six servings ÷ four servings gives a factor of 1.5. Two cups of flour becomes 3 cups, 1 1/2 tsp baking powder becomes 2 1/4 tsp and 250 g sugar becomes 375 g. The pinch of nutmeg has no number, so it stays as written.
Halve a recipe from 8 to 4 servings
Halving gives a factor of 0.5: ¾ cup butter becomes ⅜ cup (6 tablespoons), 1⅓ cups sugar becomes ⅔ cup and 400 ml cream becomes 200 ml.
Triple a sauce with a range
Going from 2 to 6 servings triples everything. The garlic range 2–3 becomes 6–9 cloves, ½ cup oil becomes 1½ cups and 1.5 tbsp lemon juice becomes 4½ tbsp.
Frequently asked questions
How do I double a recipe?+
Set the servings you need to twice the original (for example 4 → 8). Every quantity is multiplied by 2. Increase baking time slightly if you bake in one larger pan instead of two pans of the original size.
How do I scale eggs when the result is a fraction?+
Beat the eggs together and weigh or measure the portion you need: a large egg is about 50 g, or roughly 3 tablespoons, of which the yolk is about 1 tablespoon. For small differences, round to the nearest whole egg.
Should I scale salt, spices and baking powder exactly?+
For modest changes (½× to 2×) scaling everything linearly works well. For big batches, add salt, spices and chemical leaveners at around 75–90% of the scaled amount first, then adjust to taste.
Does cooking time change when I scale a recipe?+
Time depends on the thickness of the food, not the quantity. The same depth of batter in more pans bakes in the same time; a deeper pan or larger roast takes longer. Use a thermometer or doneness test.
What formats does the scaler understand?+
Whole numbers, decimals (1.5), fractions (3/4), mixed numbers (1 1/2), Unicode fractions (½, ¾, ⅓) and ranges such as 2-3 or 2 to 3 at the start of each line. Lines without a leading number are left unchanged.