Recipe Scaling Calculator

What this calculator answers

How much of each ingredient you need when you make more or less of a recipe. Paste the ingredient list, say how much you want to make, and every amount is multiplied by the same scale factor and shown as a measure you can use in a kitchen, such as ¼ cup + 1½ tsp, with the exact amount next to it. You can set the factor from servings, type it in, work it out from the one ingredient you have, or get it from the size of your pan.

How to use it

• Scale by: choose how to set the scale factor.
  • Servings: what the recipe makes and what you want to make. Any count works, as long as both use it: 24 cookies to 36 cookies is the same as 4 servings to 6.
  • A factor: a number, fraction or percentage, such as 2, 1/2, 1 1/2 or 150%.
  • An ingredient you have: how much of it you have, with the unit and its name, such as 2 eggs or 300 g flour. A word from the ingredient finds its line, and that line’s amount sets the scale.
  • Pan size: the recipe’s pan and yours, such as 8 in round, 9x13 or 23 cm round. Sizes without a unit are inches.
• Show amounts in: As recipe keeps each line in its own system and only tidies the measure (48 tsp becomes 1 cup). US shows cups, spoons, ounces and pounds; Metric shows milliliters, liters, grams and kilograms.
• Ingredients: paste the list, one ingredient per line, or choose Rows to enter the amount, unit and ingredient in separate boxes. Switching between the two carries the recipe across.

The calculator reads whole numbers, decimals with a point, fractions (3/4), mixed numbers (1 1/2, 1-1/2, 1½), the fraction characters ½ ⅓ ¼ ⅛ and the rest, and ranges (2-3, 2 to 3), which scale at both ends. Units can be written out or abbreviated (tsp, t, tbsp, T, c, fl oz, g, lb and more). A second amount in parentheses, as in 1 1/2 cups (190 g) flour, scales too, and measures added together, such as ½ cup + 2 tbsp or 1 lb 3 oz, scale as one amount, so a scaled list can be pasted back in and scaled again. Lines without an amount, such as a heading or “salt to taste”, stay as written, and the line under the list says how many lines were read.

Results update as you type. The Try buttons halve, double or make a third of the example, show it in metric, or set the scale from 2 eggs on hand. Copy scaled list copies the new ingredient list as plain text. To compare, say, a double and a triple batch, press Save for comparison, change the factor and save again.

How to scale a recipe up or down

Work out one scale factor and multiply every amount by it. The factor is what you want to make divided by what the recipe makes:

A factor above 1 makes more and a factor below 1 makes less. Doubling is a factor of 2, halving ½ and a third ⅓. Every ingredient uses the same factor, so the proportions, and the recipe, stay the same.

Worked example: pancakes for 4, scaled to 6

A pancake recipe serves 4 and you want to serve 6.

1. Scale factor: 6 ÷ 4 = 1.5.
2. Multiply each amount by 1.5 and turn the result into measures:

The milk is exact: 1.875 cups is 1¾ cups plus ⅛ cup, and ⅛ cup is 2 tbsp. So is the butter: 4.5 tbsp is 4 tbsp (¼ cup) plus ½ tbsp, which is 1½ tsp. Only the cinnamon is rounded, and 4½ eggs gets a note, because an egg doesn’t split neatly.

With Show amounts in: Metric, the same batch reads 532 mL of flour (532.32 mL exactly) and 444 mL of milk (443.6 mL exactly).

Doubling, halving and cutting a recipe into thirds

Use a factor of 2 to double, ½ to halve and ⅓ to make a third. Halves and thirds turn neat measures into awkward ones; these are the measures the calculator gives:

The University of Nebraska–Lincoln Extension’s reference table gives 6 tablespoons for half of ¾ cup. The calculator’s ⅓ cup + 2 tsp is the same 18 teaspoons in two measures.

Turning awkward amounts into cups, tablespoons and teaspoons

The calculator multiplies exactly, then picks measures you can fill. US measures follow NIST Handbook 44: 1 tbsp = 3 tsp, 1 cup = 16 tbsp = 48 tsp, 1 fl oz = 2 tbsp, 1 pint = 2 cups, 1 quart = 2 pints and 1 gallon = 4 quarts. The rules are the page’s own convention:

• Fractions of a measure are limited to ⅛, ¼, ⅓, ½, ⅔ and ¾, and the nearest one wins.
• Under 1 tbsp, amounts are in teaspoons. From 1 tbsp to under ¼ cup, they’re in tablespoons plus teaspoons. From ¼ cup up, they’re in cups. So 48 tsp shows as 1 cup, and ⅛ cup as 2 tbsp.
• One measure is used when it is within 5% of the exact amount. Otherwise the calculator fills what it can in cups and adds tablespoons and teaspoons, as in ¼ cup + 1½ tsp for 4½ tbsp.
• Fluid ounces, pints, quarts and gallons stay in their unit while the amount is at least 1 of it. Ounces become pounds from 16 oz, as in 1 lb 3 oz.
• Metric amounts are rounded to 0.5 under 10, to 1 under 1,000, and to 0.01 L or kg from there.

The Rounding column says how far each kitchen measure is from the exact amount, and in which direction. For salt, leavening and yeast, where a small difference can show, use the exact amount if you have a scale or small spoons.

Scaling from the one ingredient you have

When one ingredient is short, let it set the scale: the factor is what you have divided by what the recipe uses. With 2 eggs on hand for the pancakes, which use 3, the factor is 2 ÷ 3 = ⅔. The flour becomes 1 cup and the milk ¾ cup + 1 tbsp + 1 tsp.

What you have must be measured the same way as the recipe’s line: a count against a count, a volume against a volume, a weight against a weight. The units can differ (a pound of flour against 500 g works), and a second amount in parentheses on the line counts too.

Why the calculator won’t turn cups into grams

A cup measures volume and a gram measures weight, and linking them takes the ingredient’s density. On King Arthur Baking’s chart, a cup of all-purpose flour weighs 120 g and a cup of granulated sugar 198 g, so there is no single answer. The calculator converts cups to milliliters and ounces to grams, but never cups to grams. If you enter 300 g of flour on hand for a recipe measured in cups, it says why it can’t use it instead of guessing.

For example, 3 cups with Metric chosen shows 710 mL (709.76 mL exactly), a volume. For grams, NIST suggests measuring with the recipe’s own cup or spoon and weighing the result.

Scaling a recipe to a different pan

Compare the pans by the area of their base, so the batter keeps the same depth, as the University of Nebraska–Lincoln Extension recommends when you change pans. A round pan’s area is π × (diameter ÷ 2)²; a square or rectangular pan’s is length × width.

A cake for an 8 in round pan (50.27 sq in) moved to a 9 × 13 in pan (117 sq in) needs 117 ÷ 50.27 = 2.33 times the batter, so 1½ cups of flour becomes 3½ cups. Both pans are assumed to have straight sides and the same depth.

Eggs, leavening and seasoning: amounts that need judgment

• Eggs and other counted items: 4½ eggs gets a note. Round to a whole egg, or beat one and measure: half a large egg is about 2 tbsp, according to the University of Nebraska–Lincoln Extension.
• Pinches, dashes and handfuls: they aren’t fixed measures, so the calculator scales their count and says so. Lines like “salt to taste” stay as written.
• Leavening, salt and spices: everything is scaled in proportion, with no hidden adjustment. If you know a recipe needs gentler scaling for these, change them yourself and keep the exact amounts as your starting point.

Do cooking times and pan sizes change when you scale?

Cooking times can change, but the calculator changes amounts only. A bigger or smaller batch can cook in a different time: the University of Nebraska–Lincoln Extension notes that smaller amounts may bake in less time and suggests checking for doneness early. The oven temperature isn’t changed either. Use the pan-size option to pick a pan that keeps the batter at the recipe’s depth.

Reading the result

• Scale factor is the number every amount was multiplied by, with how it was found.
• Scaled ingredients is the new list, in the recipe’s order, ready to copy or print.
• Lines scaled, Rounded to a measure and To check by hand count what was scaled, which amounts were rounded (and the largest change), and which lines need a decision: part eggs, pinches or amounts the calculator couldn’t read.
• The table shows each line’s recipe amount as read, the kitchen measure, the exact amount and the rounding. Download it as a CSV file.
• How this was calculated shows the factor and each multiplication with your numbers.

Assumptions and limitations

• Cups, spoons, fluid ounces, pints, quarts and gallons are US measures. Write “metric cup” (read as 250 mL) or “imperial pint” for those; customary measures differ between countries, as NIST points out. If a recipe mixes US and imperial measures, the calculator warns you.
• Pints and quarts are read as US liquid measures. The US dry pint and quart are larger (NIST lists both), which matters only if you convert them to milliliters.
• “oz” is a weight and “fl oz” a volume. If a recipe gives milk or water in “oz”, it may mean fluid ounces; write fl oz to have it read as a volume.
• Numbers inside the ingredient text, such as a 14 oz can or a 1-inch piece, aren’t scaled. Neither are items the calculator treats as counts, such as sticks of butter: 1½ sticks stays in sticks.
• Up to 60 ingredient lines are read. Decimals need a point: 1,5 is refused rather than guessed.

Common mistakes

• Scaling a pan by its width instead of its area. Going from an 8 in to a 9 in round pan is 1.27 times the batter ((9 ÷ 8)² = 1.2656), not 1.125 times.
• Treating “oz” as fluid ounces. An ounce of flour by weight and a fluid ounce of flour by volume are different amounts.
• Ignoring the rounding on small amounts. A third of ½ tsp is 0.167 tsp, and the nearest spoon, ⅛ tsp, is 25% less. Check the Rounding column for baking soda, salt and yeast.
• Doubling the baking time with the recipe. The calculator doesn’t scale time, and a different amount in a different pan can cook faster or slower. Check early, and use the pan-size option to keep the depth the same.
• Mixing up a US and an imperial pint. An imperial pint is about 20% larger, so a British recipe’s 1 pint of milk is about 2.40 US cups.