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Recipe Scaler
Use this free recipe scaler to resize any recipe in seconds. Enter the servings the recipe makes and the servings you want, paste your ingredient list, and every quantity is scaled for you — fractions included. You can also scale by a straight factor, such as doubling or halving, and the calculator converts small amounts into easier units, so a quarter cup that shrinks to a tablespoon count you can actually measure.
| Original | Scaled |
|---|---|
| 2 cups flour | 5 cups flour |
| 1 cup sugar | 2 1/2 cups sugar |
| 2 tbsp butter | 5 tbsp butter |
| 1 tsp vanilla extract | 2 1/2 tsp vanilla extract |
How it works
The heart of the calculator is the scale factor. When you scale by servings, the factor is the desired servings divided by the original servings: a recipe for 4 servings scaled to 10 servings has a factor of 2.5, and a recipe for 8 servings scaled to 4 has a factor of 0.5. When you scale by factor directly, you type the multiplier yourself, which is handy for doubling, tripling, or halving a recipe without thinking about servings at all. Either way, every ingredient quantity is multiplied by that one number.
Reading your ingredient list is the clever part. Each line is parsed into a quantity, a unit, and a name. The quantity can be a whole number, a decimal, a fraction such as 1/2, or a mixed number such as 1 1/2, which the calculator reads as 1.5. The unit is the word after the quantity, such as cups, tbsp, tsp, oz, or grams, and everything after that is the ingredient name. Lines with no quantity at all, such as "salt to taste" or "a pinch of pepper," are passed through unchanged, because those are adjusted by tasting rather than by arithmetic.
After scaling, the amounts are rounded back into friendly fractions when that option is on. Nobody wants to measure 3.75 teaspoons, but 3 3/4 teaspoons is a real measuring spoon combination, and 2.5 cups is a natural amount. The calculator rounds to the nearest eighth, which covers the fractions on a standard set of measuring cups and spoons: halves, thirds, quarters, and eighths. If you prefer decimals, switch the option off and you will see numbers like 3.75 instead.
Unit conversion handles the amounts that become awkward after scaling. A cup that shrinks below a quarter of a cup is shown in tablespoons instead, since 1 cup is 16 tablespoons, and a tablespoon amount below 1 becomes teaspoons, since 1 tablespoon is 3 teaspoons. Going the other way, 16 or more tablespoons are shown as cups, and 3 or more teaspoons become tablespoons. This keeps every scaled amount in a unit you can actually measure with the tools in your drawer, instead of asking you to measure 0.06 cups of oil.
Scaling is exact for most ingredients, but baking has two honest exceptions. First, yeast and leavening such as baking powder should be scaled a little less than the full factor when you double or triple a recipe, because a very large mass of dough ferments and rises differently from a small one. Second, cooking time and pan size do not scale with the ingredients: a doubled cake needs a bigger pan or two pans, and a tripled batch of cookies is best baked in two separate batches rather than one giant tray. For very large changes, making the recipe twice is often more reliable than scaling it once.
Scaled amount = original amount × scale factor
Worked example
You have a cookie recipe that makes 4 servings, and you want 10 servings. The ingredient list is 2 cups flour, 1 cup sugar, 2 tbsp butter, and 1 tsp vanilla extract.
Step 1: Scale factor — 10 ÷ 4 = 2.5.
Step 2: Flour — 2 × 2.5 = 5 cups.
Step 3: Sugar — 1 × 2.5 = 2 1/2 cups.
Step 4: Butter — 2 × 2.5 = 5 tbsp.
Step 5: Vanilla — 1 × 2.5 = 2 1/2 tsp.
The scaled recipe is 5 cups flour, 2 1/2 cups sugar, 5 tbsp butter, and 2 1/2 tsp vanilla extract. No unit conversion is needed here, because every amount is still easy to measure. If the recipe also had 1 1/2 tsp salt, it would scale to 3 3/4 tsp, which the calculator shows as 1 1/4 tbsp.
FAQ
How do I scale a recipe up or down?
Divide the number of servings you want by the number the recipe makes to get the scale factor, then multiply every ingredient by that factor. A recipe for 4 servings scaled to 10 servings has a factor of 2.5, so 2 cups of flour becomes 5 cups. This calculator does the multiplication for every line at once, including fractions.
How do I scale a recipe with fractions like 1 1/2 cups?
Convert the mixed number to a decimal, multiply by the scale factor, and convert back to a fraction. For example, 1 1/2 cups is 1.5 cups, times a factor of 2.5 is 3.75 cups, which is 3 3/4 cups. This calculator reads fractions such as 1/2 and 1 1/2 directly and returns the scaled amounts as friendly fractions.
Can you scale a recipe down, not just up?
Yes. Scaling down works the same way, with a factor below 1. A recipe for 8 servings scaled to 4 servings has a factor of 0.5, so every ingredient is halved. Small amounts may convert to smaller units, such as 1/4 cup becoming 4 tablespoons, which is easier to measure accurately.
Do baking recipes scale the same way as cooking recipes?
Mostly, but baking is less forgiving. Flour, sugar, butter, and eggs scale linearly for modest changes, but yeast and baking powder should be scaled a little less than the full factor when you double or triple a recipe, and the baking time and pan size need adjusting separately. For large changes, it is safer to make two separate batches than one giant one.
What if an ingredient has no quantity, like salt to taste?
Ingredients without a number, such as salt to taste or a pinch of pepper, are left unchanged by the calculator because they are adjusted by tasting, not by arithmetic. Scale the measured ingredients, then season the finished dish to taste as usual.