How does the recipe scaler work?

Paste your ingredient list (one per line), enter the original number of servings and your target servings. The tool calculates a scale factor and multiplies every quantity, then formats the result as fractions or decimals.

Can I scale a recipe by a custom factor instead of servings?

Yes. Set original servings to 1 and enter your desired multiplier as the target servings (e.g., 2 for double, 0.5 for half).

What ingredient formats are supported?

The parser handles integers (2), decimals (1.5), fractions (1/2), mixed numbers (1 1/2), Unicode vulgar fractions (½), ranges (1–2 cups), and pass-through phrases like "to taste" or "a pinch".

Why are some quantities shown as fractions?

Fractions are more natural in cooking - ¼ tsp is clearer than 0.25 tsp. You can switch between fraction and decimal display using the toggle.

Recipe Scaler - Scale Any Recipe Up or Down Online

How to scale a recipe

Paste your ingredient list into the left panel (one ingredient per line), then enter the original and desired serving counts. The scaler multiplies every quantity by the ratio target ÷ original and formats the result for easy reading.

Fraction display

Cooking measurements are traditionally expressed as fractions. The tool automatically snaps scaled quantities to the nearest common cooking fraction (¼, ⅓, ½, ¾, etc.) when they fall within a small tolerance, keeping your ingredient list easy to follow. Switch to Decimal mode if you prefer numeric output.

Range ingredients

Ranges like "1–2 cups broth" are parsed and both endpoints scaled. The output shows the scaled range, e.g. "2–4 cups broth" when doubling.

Pass-through phrases

Phrases like "to taste", "a pinch", or "as needed" are passed through unchanged; they cannot be meaningfully scaled.

Cooking chemistry scaling limitations

Scaling ingredients is not always linear due to cooking chemistry:

Leavening agents: when doubling a baked recipe, baking powder and baking soda should be scaled to about 75% (not 100%) of the doubled amount. Over-leavening causes collapse and a metallic taste.
Seasoning and salt: salt perception is nonlinear. When scaling up, start at 60–70% of the mathematically correct amount and adjust to taste — you can always add more, not less.
Cooking time and temperature: cooking time does not scale with ingredient quantity. A 10 lb roast does not take twice as long as a 5 lb roast; use an internal thermometer and verify doneness.
Pan size: doubling a cake recipe into the same pan will overflow it; use a proportionally larger pan or bake in batches.

Unit conversion note

The scaler understands common cooking units: teaspoons (tsp), tablespoons (tbsp), cups, fluid ounces (fl oz), and milliliters (ml). For unusual units (a “knob of butter”, “2 sprigs”, “1 bunch”), the scaler passes the numeric value through unchanged and scales it directly — so “2 sprigs” becomes “4 sprigs” at 2× scale.