Recipe Scaler

How to use

1. 1Pick a scale method: By servings (original count and new count), By multiplier (any positive factor like 0.5 or 2), or By pan size (original pan and target pan).
2. 2Enter the inputs for that method. For By pan size, choose Round or Rectangle, set the dimensions in inches, and use the pan presets for common sizes like 9 inch round or 9 by 13.
3. 3Paste your recipe into the textarea, one ingredient per line. Headings and instruction lines without a number stay untouched.
4. 4Read the scaled recipe on the right. Each row shows the new quantity, the original value, and a short note when a countable item like eggs was rounded for cooking.
5. 5Click Copy on any line for that ingredient or Copy all to copy the full scaled recipe. Use Load sample for a worked example or Clear to start with empty text.

About this tool

Recipe Scaler rewrites every quantity in a recipe so it fits the number of people you want to feed or the pan you have on hand. Three scale methods cover every realistic use case. Pick By servings when you already know the original yield (e.g. a recipe that serves 8 and you want it to serve 12); the tool multiplies every ingredient by target divided by original. Pick By multiplier when you just want to halve a recipe, double it, triple it, or apply any custom factor like 1.5 or 0.75; one-tap presets cover the four most common factors. Pick By pan size when you are converting between baking pans of different shapes or sizes; the scale factor is the surface area ratio of the two pans (a 9 inch round pan is about 63.6 square inches, a 9 by 13 inch rectangle is 117 square inches, so a 9 inch round recipe scales by about 1.84 for a 9 by 13). Round pan area uses pi times radius squared and rectangular pans use length times width. Eight pan presets cover the most common pans (8 inch round, 9 inch round, 10 inch round, 8 by 8 square, 9 by 9 square, 9 by 13 rectangle, 11 by 15 rectangle, and 9 by 5 loaf). On the ingredient side, the parser reads any standard recipe number format: integers (3), decimals (1.5), simple fractions written with a slash (1/2, 3/4), mixed numbers (1 1/2), Unicode vulgar fractions copied from food blogs (1/4, 1/2, 3/4, 1/3, 2/3, 1/8, 3/8, 5/8, 7/8, and similar code points), and numeric ranges like '2-3 tablespoons' or '2 to 3 tablespoons'. The scaled result is formatted with cooking ergonomics: when the answer is close to a friendly fraction (halves, thirds, quarters, sixths, or eighths within 1/64), it is rendered as a mixed number like '1 1/2 cup' instead of a decimal like '1.5 cup'. Countable units (eggs, yolks, cloves, slices, sticks of butter, leaves, sprigs, cans, packets, and many produce items) round to whole numbers or to a half when scaling would otherwise yield an awkward fraction; a short inline note shows the raw scaled value so you can decide whether to bake a half batch or live with the round-up. Headings, blank lines, and instruction lines without a leading number pass through unchanged so you can paste an entire recipe block and copy a rewritten version back out. Everything happens locally in your browser: the recipe text never leaves your device, no upload is performed, and no account is required.

Free to use. Works in your browser. No signup, no login.