Recipe Scaler Calculator: Double, Halve or Resize Any Recipe
Paste a one-ingredient-per-line recipe, enter the original and desired servings, and get fraction-friendly
quantities automatically. You can also halve, double, triple, or use any custom multiplier.
Fractions, mixed numbers, ranges, metric and imperial units are supported. Your recipe is parsed locally in your browser.
Scale your recipe
4Copy your scaled recipe
Scale factor—
Desired servings—
Valid changes update this result automatically.
How to scale a recipe for the result you want
Scale by servings
Enter the original yield and desired yield. The factor is desired ÷ original; each numeric ingredient is multiplied by that factor.
Double a recipe
Choose Double for a 2× factor. For example, ¾ cup × 2 = 1½ cups.
Halve a recipe
Choose Half for a 0.5× factor. For example, 1½ cups × ½ = ¾ cup.
Use a custom multiplier
Choose Custom and enter a decimal or fraction. The desired servings update immediately to keep both methods synchronized.
What does not scale linearly
Time, oven temperature, pan geometry, fermentation, and seasoning judgment do not follow the ingredient multiplier automatically. Treat the calculated amount as a baseline.
Worked recipe-scaling examples
Scenario
Before
Calculation and result
Try it
Halve a recipe
4 → 2 servings 1½ cups flour 2 eggs salt to taste
1½ × ½ = ¾ cup flour 2 × ½ = 1 egg salt to taste stays unchanged
Ingredient quantities usually provide a dependable proportional starting point. The following adjustments require the original recipe's cues, suitable equipment, and sometimes a test batch.
Cooking time and heat
Do not multiply time by the scale factor. Food depth, surface area, airflow, vessel material, and oven load change heat transfer. Keep the tested temperature initially and use visual cues plus a food thermometer when appropriate.
Pan capacity
Compare usable pan volume and fill depth. Splitting a larger batch across pans may keep depth similar; putting it into one deeper pan can change both timing and doneness.
Eggs
For part of an egg, beat it until uniform and measure the needed share by weight or volume. Cook promptly. Use pasteurized egg products when a finished recipe will be raw or undercooked.
Salt and spices
The proportional result is a baseline, not a universal sensory rule. When practical, add part, taste at a safe stage, and adjust—especially after a large increase.
Yeast
Fermentation depends on dough temperature, time, hydration, inoculation, and batch handling. Use the proportional quantity as a starting point and judge the dough rather than the clock alone.
Chemical leaveners
Baking soda and baking powder interact with acids, liquids, mixing, pan depth, and bake time. Scale them proportionally for modest changes, but test substantial changes instead of assuming identical lift.
References: USDA Food and Nutrition Service guidance emphasizes measured portions and recipe-yield data in its Food Buying Guide. USDA FSIS provides safe handling guidance for shell eggs, including pasteurized products for raw or undercooked recipes.
Rounding and unit rules
Kitchen-fraction mode rounds volume and count quantities to the nearest allowed denominator (4, 8, or 16). A result is labeled “rounded” whenever it differs from the exact multiplication. Weight units—milligrams, grams, kilograms, ounces, and pounds—use the chosen decimal precision. Teaspoons of 3 or more are normalized to tablespoons, and tablespoons of 16 or more to cups; the exact pre-conversion amount remains visible. Other units are preserved as entered. This tool does not make ingredient-dependent cups-to-grams conversions.
Written and reviewed by: Starlight Tools Editorial Team. Editorial calculator review only; this guidance is not a substitute for a tested production recipe. Last reviewed: 17 July 2026.
Recipe scaler FAQs
How do I double or halve a recipe?
Paste the ingredients, then choose Double or Half. The calculator sets the factor to 2 or 0.5 and keeps the target servings synchronized.
How do I enter fractions and mixed numbers?
Type common notation such as 1/2, ¾, 1 1/2, 1.5, or a range such as 2–3 at the start of an ingredient line.
How should I divide an egg?
For a fractional egg, beat it until uniform and measure the required fraction by weight or volume. Cook it promptly, and use pasteurized egg products for recipes served raw or undercooked.
Does cooking time change when I scale a recipe?
Usually, but not in direct proportion to the ingredient factor. Food depth, pan geometry, batch arrangement, and heat transfer determine the timing, so use the recipe's doneness cues and a thermometer where appropriate.
Should I change the oven temperature?
Not automatically. Start with the recipe's stated temperature unless a tested version or equipment guidance says otherwise, then adjust pan capacity and check earlier when food is shallower or split across pans.
Do salt, spices, yeast, and leaveners scale exactly?
The calculator shows the proportional baseline, but large batch changes may need testing. Salt and spices should be adjusted to taste; yeast depends on fermentation time and dough conditions; baking soda and baking powder depend on the formula's acids, liquids, and pan geometry.
Are pasted recipes stored or uploaded?
No. Parsing and calculations happen in your browser. A recipe leaves the page only if you deliberately use Share, which places the recipe state in the share URL.
