Recipe Scaler Calculator
Scale a recipe's ingredient list to a new number of servings or by any factor, with fractions read and teaspoons, tablespoons and cups tidied up.
Result…
How it's calculated
Scale factor = servings you want ÷ servings the recipe makes New amount = old amount × scale factor 3 tsp = 1 tbsp · 16 tbsp = 1 cup (48 tsp) · 1000 mL = 1 L · 1000 g = 1 kg · 16 oz = 1 lb
Multiplies every amount in a recipe by one scale factor: the servings you want divided by the servings the recipe makes, or a factor you choose (2 to double, 0.5 to halve). It reads whole numbers, decimals, fractions like 1/2, mixed numbers like 1 1/2 and fraction characters like ½. Tidying rewrites US spoon and cup measures in the largest sensible unit (48 tsp becomes 1 cup, 4.5 tbsp becomes 1/4 cup + 1 1/2 tsp), turns 1500 g into 1.5 kg and 20 oz into 1 lb 4 oz, and never mixes metric and US units. Eggs are rounded to whole eggs with a note. Seasoning, leavening, pan size and cooking time often need a cook's judgement when a recipe is scaled a long way.
Your numbers, step by step
About the Recipe Scaler calculator
This recipe scaler resizes a whole ingredient list at once: paste the recipe one ingredient per line, say how many servings it makes and how many you need, or give a factor such as 2 to double or 0.5 to halve, and every amount is multiplied by the same scale factor. It reads the way recipes are written: whole numbers, decimals, fractions like 1/2, mixed numbers like 1 1/2 and characters like ½. With tidying on, awkward results are rewritten in the largest sensible unit of the same system, so 48 teaspoons become 1 cup, 1500 g becomes 1.5 kg and 20 oz becomes 1 lb 4 oz; metric and US units are never mixed. Eggs are rounded to whole eggs with a note, and lines without an amount, like salt to taste, are kept as written. The working shows each line's multiplication. To weigh rather than measure, the cups to grams converter helps.
How to use it
- Under “Scale by”, choose “Servings” or “A factor”.
- Enter “Recipe serves” and “Servings you want”, or the “Scale factor”.
- Paste the list into “Ingredients (one per line)”, each line starting with its amount and unit, like “1 1/2 tsp salt”.
- Leave “Units” on “Tidy up” to convert spoons to cups and grams to kilograms, or choose “Keep my units”.
- Read the scale factor and each new amount; the working lists every line.
Worked example
A recipe for 4 needs to serve 10, so the scale factor is 10 ÷ 4 = 2.5. Then 1 1/2 cups of flour × 2.5 = 3 3/4 cups, 2 tbsp of sugar × 2.5 = 5 tbsp, which tidies to 1/4 cup + 1 tbsp, 1/2 tsp of salt becomes 1 1/4 tsp, 2 eggs become 5 eggs and 200 mL of milk becomes 500 mL.
Updated
Questions people ask
How do I scale a recipe up or down?
Divide the servings you want by the servings the recipe makes to get the scale factor, then multiply every ingredient by it. From 4 servings to 6 the factor is 1.5.
How many teaspoons are in a tablespoon and a cup?
In US measures, 3 teaspoons make a tablespoon and 16 tablespoons, or 48 teaspoons, make a cup. Metric and Australian spoons differ slightly, so the tidy-up uses US spoons and cups.
What do I do with half an egg?
The calculator rounds eggs to whole ones and says so. For a closer match, beat the eggs and use part by weight; King Arthur Baking lists a large egg at about 50 g without the shell.
Do baking times change when I double a recipe?
Often, yes, but not in proportion. A deeper or larger pan can need more time at the same or a slightly lower temperature, so check doneness rather than doubling the time.
What doesn't scale well?
Leavening, yeast, salt and strong spices can taste or behave differently when a recipe is scaled a long way, and pan sizes and cooking times rarely scale in a straight line. Scale them, then adjust by taste and by eye.