How to Double or Halve Any Recipe (the Easy Way)

You found a recipe that serves 4, but you're cooking for 8 — or just for yourself. Resizing a recipe sounds fiddly, but it comes down to a single number called the scale factor. Get that, and every ingredient follows.

This guide shows you exactly how to double, halve, and resize any recipe — plus a quick measurement chart and a free recipe scaler that does the math instantly. For changes beyond straight scaling — like halving a recipe and making it gluten-free at the same time — you can edit the recipe with AI instead.

The One Rule: Find Your Scale Factor

The scale factor is the servings you want divided by the servings the recipe makes:

Doubling? Scale factor = 2. Multiply every ingredient by 2.
Halving? Scale factor = 0.5. Divide every ingredient by 2.
Recipe makes 4, you want 6? 6 ÷ 4 = 1.5. Multiply everything by 1.5.

That's the whole trick. The only hard part is the arithmetic on fractions — which is exactly what a calculator is for.

How to Double a Recipe (2×)

Multiply each quantity by two. Whole numbers are easy; the fractions are where people slip up. Here's a quick reference for doubling common measurements — or paste your ingredient list into the free recipe doubler and every line is multiplied for you:

Original	Doubled
¼ cup	½ cup
⅓ cup	⅔ cup
½ cup	1 cup
¾ cup	1½ cups
1 tsp	2 tsp
1 tbsp	2 tbsp

How to Halve a Recipe (0.5×)

Divide each quantity by two. The awkward ones are odd fractions and single eggs:

¾ cup halved = 6 tablespoons (because ¼ cup = 4 tbsp, so ⅜ cup = 6 tbsp).
⅓ cup halved ≈ 2 tbsp + 2 tsp.
1 egg halved: beat the egg, then use half by weight (about 25 g), or just use one whole egg for forgiving recipes like soups and stews.

The free recipe halver converts these to the nearest sensible measurement automatically, so you don't have to keep a fraction chart on the fridge.

Scaling to Any Number of Servings

The same formula handles any target. Recipe serves 6 and you need 10? 10 ÷ 6 ≈ 1.67, so multiply everything by 1.67. Paste your ingredients into the recipe scaler, set the new servings, and every line updates in proportion.

What Doesn't Scale Linearly

Most ingredients scale cleanly, but a few don't — keep these in mind:

Cook and bake times: a doubled cake doesn't bake twice as long. Use a bigger pan or two pans and check for doneness early.
Salt, spices, and leavening: these can taste too strong when scaled up. Scale them, then taste and adjust.
Pan and pot size: doubling a one-pan dish may need a wider pan so it cooks evenly rather than steaming.

The Fastest Way: Let a Tool Do It

You can do all of this by hand, but it's faster to let a calculator handle the fractions:

Use the free recipe scaler to paste ingredients and double, halve, or resize to any servings.
Just doubling or halving? The one-tap recipe doubler and recipe halver are preset versions of the same tool.
Use the recipe converter to paste a recipe URL and get a clean, ad-free recipe you can scale, convert units on, and save.
Cooking from it tonight? Save it and open Cook Mode for a step-by-step view with built-in timers.

Frequently asked questions

How do I double a recipe?

To double a recipe, multiply every ingredient quantity by 2. For fractions: ¼ cup becomes ½ cup, ¾ cup becomes 1½ cups, and 1 egg becomes 2. A recipe scaler does this instantly so you do not have to convert fractions by hand.

How do I halve a recipe?

To halve a recipe, divide every ingredient by 2. The tricky ones: ¾ cup halved is 6 tablespoons, and a single egg halved is about 25 g of beaten egg (or just use one whole egg in forgiving recipes).

What is the scale factor for resizing a recipe?

The scale factor is the servings you want divided by the servings the recipe makes. A recipe for 4 scaled to 6 has a scale factor of 1.5, so you multiply every ingredient by 1.5.

Does cook time double when I double a recipe?

No. Cook and bake times do not scale linearly. Use a larger pan or multiple pans when doubling, and check for doneness early rather than simply doubling the time.

Is there a free recipe scaling calculator?

Yes. The Drizzlelemons recipe scaler lets you paste ingredients and double, halve, or resize to any number of servings for free, with no sign-up required.