How to double, halve or scale a recipe

Last updated October 23, 2026

To double a recipe, use twice as much of every ingredient. To halve it, use half. To cook for some other number of people, divide how many you’re cooking for by how many the recipe serves, and multiply every amount by that. The amounts are the easy part. When a doubled recipe goes wrong, it’s usually the pan, the timing or the salt, so here’s what to watch.

Cooking for a different number of people

Divide how many you’re cooking for by how many the recipe serves. That’s the number to multiply every amount by.

• A recipe for 4, cooked for 8: 8 ÷ 4 = 2, so double every amount.
• A recipe for 6, cooked for 3: 3 ÷ 6 = ½, so halve it.
• A recipe for 4, cooked for 6: 6 ÷ 4 = 1½, so multiply every amount by 1½.

Write the new amounts down before you start. Halfway through a recipe is the worst time to work out half of ⅓ cup.

Halving and doubling chart

Cups and spoons don’t always halve neatly: half of ⅓ cup is 2 tablespoons and 2 teaspoons. Here’s what the common amounts come to, in measures you’ll find in an ordinary set of cups and spoons.

The American Egg Board counts about 5 large eggs to the cup, so one beaten egg is a little over 3 tablespoons and half of one is about 1½. In grams and milliliters there are no odd halves at all, so a recipe in cups can be easier to scale once it’s converted to metric.

What doesn’t double

Most of a recipe doubles without a second thought. These are the parts that need one.

The pan

Twice the batter needs room for twice the batter. Pour it all into the pan the recipe asks for and it’ll be twice as deep: it may spill over, and the middle stays raw long after the edges are done. The easy way out is two pans of the same size, side by side in the oven. If you’d rather use one, a 9 × 13-inch pan holds about as much as two 8-inch square pans or two 9-inch round ones.

The same goes for pots. Leave room at the top, because a soup that’s twice as full has nowhere to go when it starts to bubble.

The time

A doubled dish takes a little longer, not twice as long, the same way a full kettle takes longer to boil than a half-full one. When Milk Street baked a double batch of brownies in one bigger pan, it took five minutes more. Leave the oven where the recipe says, start checking at the time it gives and go by what it says done looks like: a skewer that comes out clean, a sauce that coats a spoon. In two pans of the original size, the time hardly changes.

On the stove, don’t pile twice the meat or vegetables into one pan. They’ll steam instead of browning, so brown them in two goes.

Salt and spices

Start with one and a half times the salt and spices, taste and add the rest if it needs it. You can always add more salt, but you can’t take it out. Cakes and cookies are the exception: you can’t taste them until they’re baked, so measure their salt exactly.

Baking powder, baking soda and yeast

Double them with everything else. A bread dough twice the size may rise a little faster or slower, so let it rise until it looks the way the recipe says, “doubled in size”, rather than for the time it gives.

One double batch or two?

A double batch saves washing up, but it has to fit. Two batches of the original size are the better choice when:

• the dough or batter would fill your bowl or mixer past what it can mix evenly
• the recipe needs a pan size you don’t have
• you’re making the recipe for the first time and don’t know how it behaves

And if the double batch is for an occasion, a birthday or a dinner for twelve, try it once before the day. Ina Garten does the same: test the bigger batch when it doesn’t matter, and adjust from there.

Halving a recipe

Halving has its own small puzzles: half an egg, odd measures and a smaller pan. Use the chart for the amounts, and for the egg, beat it and use half. Bake in a smaller pan so the batter is as deep as before: an 8-inch square or a 9-inch round instead of a 9 × 13. In the usual pan, a half batch spreads thin and bakes faster, so check it early.

Scale a recipe with Scappi

In Scappi, you choose how many times to make a recipe, from once to four times. Every amount changes, in the ingredients and in the steps too, so a step that says how much butter to stir in says the new amount while you cook. The amounts come out in measures you can fill, like 2 tbsp + 2 tsp rather than 0.17 cups, in US cups and spoons or in metric. Sizes and temperatures stay as they are: a recipe made twice still cuts its cubes the same size and bakes at the same heat.

Scappi doesn’t offer half a recipe as a button, because a recipe written to fill one pan doesn’t make half as much in half the time. For that, or for fitting a recipe to the pan you have, ask Scappi in the recipe’s chat. It changes the amounts, the pan and the times together, and shows you every change before it’s saved. The free plan includes 6 edits from the chat, and Scappi Pro has no limit.

No iPhone at hand? Paste a recipe link into the recipe converter, and Scappi emails you a clean copy of the recipe that you can make twice, three or four times, in US cups or metric.

Frequently asked questions

Do you double every ingredient when doubling a recipe?

Double every amount, then watch what doesn’t follow the math. Taste a doubled dish before you add the last of the salt, bake it in two pans or one twice the size and keep the oven at the same temperature.

Does doubling a recipe double the cooking time?

No. A double batch usually needs a few minutes more, and more again in a deeper pan. Start checking at the time the recipe gives and go by how the dish looks.

Can you halve an egg?

Yes. Beat the egg and measure out half, about 1½ tablespoons for a large egg.

Should I mix a double batch all at once or in two batches?

All at once if your bowl and mixer have room and you know the recipe. Otherwise make two batches of the original size.

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