Recipe Scale Conversion Calculator

How to Scale a Recipe

Whether you're doubling a family recipe for a crowd or cutting a batch down to a single serving, scaling accurately comes down to three steps: work out a conversion factor, apply it to every ingredient, and — optionally — tidy up the resulting measurements so they're easy to work with in the kitchen.

Step 1: Find the Conversion Factor

The conversion factor is the ratio between how much you want and how much the recipe already makes:

Doubling a recipe gives a factor of 2. Making a third of it gives a factor of 1÷3, or about 0.33. If you'd rather think in servings than a raw multiplier, switch the calculator above to Convert by Portions and let it work the factor out for you.

Step 2: Multiply Every Ingredient

Apply the same conversion factor to every ingredient in the recipe — quantities only, never the number of steps or the cooking method. For example, with a conversion factor of 2, a recipe that calls for 3 tablespoons of an ingredient needs 2 × 3 = 6 tablespoons once scaled.

Step 3: Simplify the Measurements

This step is optional, but it's what makes a scaled recipe easy to actually cook from. If tripling a recipe turns 4 ounces of butter into 12 ounces, it's often cleaner to write that as 1½ sticks or 3&frac4; cup, depending on how you measure. Converting up to the next sensible unit (ounces to pounds, teaspoons to tablespoons, and so on) keeps the ingredient list readable.

Common Kitchen Conversions

Handy for Step 3 above — use these to simplify a scaled measurement into a more natural unit.

For anything outside this list, the Volume Converter and Weight Converter handle any unit pair directly.

Things to Consider When Scaling a Recipe

Measuring by Weight vs. Volume

The bigger a batch gets, the more small volume-measuring errors add up. Dry ingredients like flour and sugar in particular can compact differently depending on how they're scooped, so a "cup" of flour can vary by 10-20% between two cooks. Where possible, weigh dry ingredients on a kitchen scale instead of measuring by volume — it's the single biggest accuracy improvement you can make when scaling a recipe up.

Cooking and Baking Times Don't Scale the Same Way

Ingredient quantities scale linearly, but cooking time doesn't — a cake batter that takes 30 minutes at one size won't take double that just because you doubled the batter. Larger or deeper dishes usually need a longer bake at the same temperature (or the same time at a slightly lower temperature), while halved recipes often cook faster than the original time suggests. Start checking for doneness earlier than the original recipe recommends, especially the first time you make a scaled version.