How to Scale a Recipe Up or Down (With Examples)

Cooking for two when a recipe serves eight? Feeding a crowd when a recipe only makes four? Scaling recipes is a core kitchen skill — and once you understand the basic math, it becomes second nature. Here's everything you need to know.

The Basic Formula

Scaling a recipe comes down to one formula: divide the desired servings by the original servings to get your scaling factor, then multiply every ingredient by that number.

Scaling factor = desired servings ÷ original servings

For example, if a recipe serves 4 and you want to make it for 10, your scaling factor is 10 ÷ 4 = 2.5. Multiply every ingredient by 2.5.

Worked Example

Original recipe (serves 4): 2 cups flour, 1 cup sugar, ½ cup butter, 2 eggs, 1 tsp baking powder

Scaling to serve 10 (factor = 2.5):

• Flour: 2 × 2.5 = 5 cups
• Sugar: 1 × 2.5 = 2.5 cups
• Butter: ½ × 2.5 = 1¼ cups
• Eggs: 2 × 2.5 = 5 eggs
• Baking powder: 1 × 2.5 = 2.5 tsp

Use our Recipe Multiplier to do this automatically for any recipe.

What Doesn't Scale Linearly

Salt and spices: Don't scale these 1:1. If you're doubling a recipe, start with 1.5x the salt and spices, then taste and adjust. Flavor compounds don't multiply evenly.

Leavening agents: Baking powder and baking soda don't always scale perfectly. For larger batches, use slightly less than the calculated amount — too much leavening can cause baked goods to rise too fast and then collapse.

Cooking time: Bigger batches don't take proportionally longer. Two pans of the same item take roughly the same time as one. A larger single item (like a doubled cake in a bigger pan) will take longer but not twice as long. Use a thermometer or toothpick test rather than relying purely on time.

Pan Size Matters

When scaling baked goods, the pan size needs to change proportionally. Doubling a recipe and putting it in the same pan will overflow and bake unevenly. A general guide:

• 2× a 9-inch round cake → use a 13×9 pan
• 2× an 8×8 square pan → use a 9×13 pan
• For cookies, just bake in multiple batches

Scaling Down: Common Challenges

Scaling down is often trickier than scaling up. The main challenge is eggs — you can't use half an egg easily. Solutions include using just the yolk or just the white, or using a small egg instead of a large one. For very small batches, consider using a recipe specifically designed for smaller yields.

The Fast Way

Skip the manual math with our Recipe Multiplier tool. Enter the original servings, the servings you need, and your ingredient amounts — it does the rest.

Frequently Asked Questions

What ingredients don't scale linearly?

Leavening agents (baking powder, baking soda, and yeast), salt, and strong spices don't always scale proportionally. When doubling or tripling a recipe, start with 75% of the calculated amount for these ingredients and adjust to taste. Salt and spices can always be added at the end; leavening errors are harder to fix once baked.

How do I scale cooking time when I change recipe size?

Cooking time doesn't scale linearly with quantity. Doubling a recipe doesn't double the cook time — typically it adds 25–50%. The key factor is the thickness of the food, not the total volume. For baked goods, use the same size pan as the original recipe and check doneness at the original time plus 20–30% for doubled batches.

Can I halve a recipe that uses eggs?

Yes, but eggs are tricky to halve exactly. For half an egg: beat the egg fully, then measure out half by volume (a large egg is about 3 tablespoons; half is 1.5 tablespoons). For baking, the easiest solution is to use a smaller egg — a medium egg is roughly half the volume of a jumbo egg.