Recipe Scaler

How to use the recipe scaler

1. Paste the ingredient list, one ingredient to a line.
2. Set what the recipe currently serves and what you need.
3. Read the scaled list, and check anything flagged as not dividing cleanly.

About this tool

Scaling a recipe is simple arithmetic done badly under time pressure. Two thirds of three quarters of a cup is a calculation nobody wants to repeat nine times with floury hands, and the usual result is one ingredient scaled and another forgotten. Paste the ingredient list here, set the servings, and every quantity moves together.

The answers come back as fractions because that is what a kitchen can measure. A scale factor of 1.5 applied to three quarters of a teaspoon gives 1.125, and no measuring spoon expresses that — so it is written as 1 1/8, rounded to the nearest eighth, third or half that a real spoon can hold. Mixed numbers, unicode fractions copied from a website, and ranges such as 1–2 tablespoons are all understood.

Lines with no leading quantity are left exactly as they were, which is deliberate. An oven temperature does not scale with the quantity, and neither does a cooking time: doubling a cake mixture means a longer bake at the same temperature, or two tins, not twice the time. Scaling those numbers would produce confident nonsense.

Eggs are the honest limitation, and the tool flags them rather than silently suggesting one and a half. So do cloves, tins and packets. Where you need half an egg, beat one and weigh out about 25 grams.

Common uses

• Cooking a recipe written for four when six people are coming.
• Halving a cake recipe to fit a smaller tin.
• Scaling a batch up for a party without recalculating each line.

Frequently asked questions

Does it scale cooking times too?

No, and deliberately so. Time does not scale with quantity — a double batch usually needs a longer bake at the same temperature, or two tins, so multiplying the time would be wrong.

What happens to eggs when I halve a recipe?

They are flagged rather than silently halved. Beat a whole egg and weigh out about 25 grams if you need half, or adjust the batch to a whole number of eggs.

Why are results shown as fractions?

Because measuring spoons and cups are marked in halves, thirds, quarters and eighths. A result of 1.125 teaspoons is unusable; 1 1/8 is something you can measure.