How recipe scaling works
Every ingredient is multiplied by the same factor: target servings ÷ original servings. Going from 8 to 12 servings is a factor of 1.5, so 2 cups of flour becomes 3 cups and 1 tsp of soda becomes 1 1/2 tsp. The tool reads the numbers at the start of each line, including fractions like 1 1/2 and 3/4, and returns amounts you can actually measure.
Why fractions instead of decimals
A measuring cup is marked in quarters and thirds, not in 0.375. Results are rounded to the nearest eighth and shown the way a recipe would write them — so you never have to convert 0.667 cups in your head while your hands are covered in flour.
What does not scale linearly
- Salt and strong spices: start at 75% of the scaled amount and adjust
- Leaveners: baking powder and soda above ~2× can taste soapy — split into batches instead
- Eggs: half an egg is awkward; beat one and weigh half (about 25 g)
- Pan size: doubling a cake recipe into the same tin overflows it — use the pan converter
- Cooking time: a larger volume needs longer; use the cooking time calculator
Scaling down safely
Halving works for most savoury dishes, but custards, breads and anything relying on gluten development behave differently at small volumes. For baking, prefer making the full batch and freezing half over trying to halve a single egg.
Frequently Asked Questions
Can I scale by weight instead of servings?
Yes — enter any two numbers that represent the same recipe, for example 1 and 1.75 for a 75% batch.
Why do some lines stay unchanged?
Lines without a leading number ("salt to taste", "Bake at 350°F") are left alone so instructions survive the scale.
Does it handle fractions in the input?
Yes: 1 1/2, 3/4 and 0.5 are all read correctly.
Privacy & Your Data
KitchenCalcHub runs entirely in your browser. Recipes, measurements and conversions are processed on your device and never uploaded — there is no server to store them.