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Recipe Scaler

Make a recipe bigger or smaller: resize up to ten ingredient amounts for a new number of servings, in units that are easy to measure.

Level: Grades 5–6

  • Common Core standard 6.RP.A.3Use ratio and rate reasoning to solve real-world and mathematical problems, e.g., by reasoning about tables of equivalent ratios, tape diagrams, double number line diagrams, or equations.
  • Common Core standard 5.NF.B.6Solve real world problems involving multiplication of fractions and mixed numbers, e.g., by using visual fraction models or equations to represent the problem.
Printable worksheet

Recipe Scaler

Know the answer you need? Pick an input to work backward.

Inputs

Result

Scale factor

1.5 ×

Multiply every amount by 1.5 to go from 4 to 6 servings.

Ingredient 1
3 cup2 cup → about 3 cup
Ingredient 2
2.25 tsp1.5 tsp → about 2 1/4 tsp
Ingredient 3
4.5 tbsp3 tbsp → about 4 1/2 tbsp
Ingredient 4
3 each2 each → 3 each
Ingredient 5
172.5 g115 g → 172.5 g

See the step-by-step solution ↓

Scaled ingredients
Scaled ingredients
IngredientOriginalScaledTo measure
Ingredient 12 cup3 cupabout 3 cup
Ingredient 21.5 tsp2.25 tspabout 2 1/4 tsp
Ingredient 33 tbsp4.5 tbspabout 4 1/2 tbsp
Ingredient 42 each3 each3 each
Ingredient 5115 g172.5 g172.5 g

Step-by-step solution

  1. Find the scale factor: the servings you want ÷ the servings the recipe makes

    64=1.5

  2. Ingredient 1: multiply 2 cup by the scale factor, so it keeps the same share of the dish

    2 cup×1.5=3 cup

  3. Ingredient 2: multiply 1.5 tsp by the scale factor, so it keeps the same share of the dish

    1.5 tsp×1.5=2.25 tsp

  4. Ingredient 3: multiply 3 tbsp by the scale factor, so it keeps the same share of the dish

    3 tbsp×1.5=4.5 tbsp

  5. Ingredient 4: multiply 2 each by the scale factor, so it keeps the same share of the dish

    2 each×1.5=3 each

  6. Ingredient 5: multiply 115 g by the scale factor, so it keeps the same share of the dish

    115 g×1.5=172.5 g

Test yourself

20 quick questions built from this calculator's formula: work out results, predict what happens when an input changes, and work backward from an answer. Every answer comes with the working.

What this calculator does

Make a recipe bigger or smaller for the number of people you're feeding. Recipes are written for a set number of servings, and dinner rarely matches. To scale a recipe, you multiply every ingredient by the same number, called the scale factor. It's the servings you want divided by the servings the recipe makes.

Going from 4 servings to 6 multiplies everything by 1.5. Going from 8 to 2 multiplies by 0.25.

The multiplying is easy, but the results are often awkward. Nobody wants to measure 4.5 tablespoons or 0.1875 cup. This scaler multiplies up to ten amounts at once. If you leave the option on, it also rewrites each one in the unit that's easiest to measure. For example, it uses cups instead of a pile of tablespoons, or kilograms instead of 1,500 grams.

Where it's used

Why this math matters outside the classroom:

  • Scale factor. Turning a 4-serving recipe into 6 servings uses a scale factor of 6 ÷ 4 = 1.5, so 2 cups of broth becomes 3.
  • Fraction amounts. At a scale factor of 1.5, 3/4 cup of milk becomes 1 1/8 cups.
  • Easier units. Halving 1/4 cup gives 2 tablespoons, since a quarter cup holds 4 tablespoons.
  • Holiday cooking. Hosts scale a family recipe from 6 to 15 servings, a factor of 2.5, before shopping for a large gathering.
  • School kitchens. School kitchens scale a tested recipe for 25 servings up to 200, which is a factor of 8.

Grade level and standards: Grades 5–6; Common Core State Standards for Mathematics 6.RP.A.3, 5.NF.B.6. © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.

How to use it

  1. Enter how many servings the recipe makes and how many you want.
  2. Type each ingredient amount and choose its unit. Leave unused rows empty.
  3. Keep 'Convert scaled amounts to friendlier kitchen units' ticked to get amounts you can measure. Untick it to keep every ingredient in its original unit.
  4. Read the scaled list. Each result shows the original amount, the scaled amount, and the nearest common kitchen fraction for cups and spoons.

What the inputs mean

Servings the recipe makes
The number of servings printed on the recipe. If it gives a range such as 4–6, pick the number you trust. The scale factor is only as good as this figure.
Servings you want
Any number above zero. Decimals work, so 2.5 servings is fine.
Convert scaled amounts to friendlier kitchen units (for example 12 tbsp → 3/4 cup)
US cups, tablespoons and teaspoons are swapped for one another only when the result lands close to a common fraction. Metric amounts switch between g and kg, or mL and L, at 1,000. Weight ounces become pounds from 16 oz. Fluid ounces and counted items stay as they are.

Formula and method

scale factor = desired servings ÷ original servings
scaled amount = original amount × scale factor
1 cup = 16 tbsp = 48 tsp; 1 lb = 16 oz; 1 kg = 1,000 g; 1 L = 1,000 mL

Every ingredient is multiplied by the same number, so the recipe's balance of flavors stays exactly the same. The unit changes afterward use exact definitions. They never change the amount, only how it's written. (tbsp is tablespoons, tsp is teaspoons, oz is ounces, g is grams and mL is milliliters.)

For cups, tablespoons and teaspoons, the scaler tries the largest unit first. It uses that unit if the amount is at least 1 tablespoon (or 1/4 cup). It must also be within 5% of a fraction you can measure with standard spoons and cups.

Worked example

A recipe for 4 uses 2 cups of flour, 1.5 tsp of baking powder, 3 tbsp of butter, 2 eggs and 115 g of sugar. You're cooking for 6.

  1. Scale factor: 6 ÷ 4 = 1.5.
  2. Flour: 2 cups × 1.5 = 3 cups. Baking powder: 1.5 tsp × 1.5 = 2.25 tsp, about 2 1/4 tsp.
  3. Butter: 3 tbsp × 1.5 = 4.5 tbsp. In cups that's 0.28125, which isn't a clean measure, so it stays as 4 1/2 tbsp.
  4. Eggs: 2 × 1.5 = 3. Sugar: 115 g × 1.5 = 172.5 g.

Result: Multiply everything by 1.5: 3 cups flour, 2 1/4 tsp baking powder, 4 1/2 tbsp butter, 3 eggs and 172.5 g sugar.

Understanding the result

A scale factor above 1 makes the recipe bigger, and one below 1 makes it smaller. A factor of 2 doubles it exactly.

Part of an egg is common when scaling. Beat the eggs together and measure by weight or volume. A large egg is roughly 50 g out of the shell, so 1.5 eggs is about 75 g.

Assumptions and limitations

  • Every ingredient grows or shrinks in step with the number of servings.
  • Cups and spoons are US measures (1 cup = 236.59 mL).
  • Cooking time and pan size don't scale in step. A doubled cake in a deeper pan needs a longer, sometimes cooler bake. A bigger pot of soup takes longer to come to a boil.
  • Seasonings, leavening (like baking powder) and thickeners sometimes need less than a straight multiple when a recipe is scaled up a lot. Taste and adjust.
  • The scaler doesn't convert between weight and volume. Use the grams to cups converter for that, because it depends on the ingredient.

Frequently asked questions

How do I scale a recipe that serves 6 down to 2?

Divide 2 by 6 to get a factor of about 0.333. Then multiply each amount by it. 1 1/2 cups becomes 1/2 cup and 3 tbsp becomes 1 tbsp. Enter 6 and 2 above, and the scaler does every line at once.

Should I scale baking recipes by weight?

Yes, if you can. Weights multiply cleanly and avoid the rounding that comes with cups and spoons. Baker's percentages make scaling bread especially easy. They give every ingredient as a share of the flour.

What do I do with half an egg?

Whisk one egg, then use half of it by weight or volume. A large egg is about 3 1/4 tbsp beaten, so half is a little over 1 1/2 tbsp.

Why didn't my tablespoons turn into cups?

The scaler only switches units when the new amount is easy to measure. 4.5 tbsp is about 0.28 cup, which has no standard measure. So it's clearer to keep it in tablespoons.

How this calculator is checked

Method: Direct proportion (scale factor = desired ÷ original servings) with exact US customary and metric unit definitions. The calculation is covered by automated tests with known reference values and edge cases. Last updated 2026-10-18. Found a problem? Tell us.

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