How the Recipe Portion Adjuster works

The core idea is simple: if a recipe makes O servings and you want D servings, every ingredient amount gets multiplied by a scale factor.

Scale factor = D ÷ O

If an ingredient amount is A (for example, 2 cups of flour), then the adjusted amount is:

Adjusted amount = A × (D ÷ O)

• Reads your servings: Original + desired servings define the scale factor.
• Parses ingredient lines: If a line begins with a number, it attempts to scale it.
• Supports real-world formats: decimals (1.5), fractions (3/4), mixed numbers (1 1/2), and ranges (2–3).
• Keeps text intact: It scales the number(s), and leaves “cups flour” or “cloves garlic” unchanged.
• Optional rounding: Great when you want cook-friendly amounts (nearest 1/4, 1/2, etc.).

Cooking is forgiving, baking is less forgiving. If you’re scaling a soup from 4 to 10 servings, rounding to the nearest 1/4 is usually fine. But if you’re scaling a cake, you may prefer No rounding and then weigh ingredients for best results. This calculator lets you choose your preferred trade-off: precision vs simplicity.

Some ingredients are written as ranges, like “2–3 cloves garlic”. This tool scales both ends (2 and 3) so you get a new range that preserves the author’s intent: a minimum and maximum that still “feels right” for taste.

Scaling examples you can copy

Here are realistic examples showing exactly what happens when you scale servings.

Original servings: 4 → Desired servings: 10
Scale factor = 10 ÷ 4 = 2.5×

• 2 cups flour → 2 × 2.5 = 5 cups
• 1 1/2 tbsp sugar → 1.5 × 2.5 = 3.75 tbsp (rounding to 1/4 → 3 3/4 tbsp)
• 3/4 tsp salt → 0.75 × 2.5 = 1.875 tsp (rounding to 1/8 → 1 7/8 tsp)
• 2–3 cloves garlic → (2–3) × 2.5 = 5–7.5 cloves (smart output → 5–7 1/2 cloves)

Original servings: 8 → Desired servings: 4
Scale factor = 4 ÷ 8 = 0.5×

• 1 lb chicken → 0.5 lb chicken
• 2 cups rice → 1 cup rice
• 1/2 cup sauce → 1/4 cup sauce

If you meal prep lunches, scaling to exactly 5 servings helps avoid leftovers you don’t want. Use rounding “none” and weigh ingredients if you’re tracking macros.

For salt, chili flakes, and strong spices: scale them, then taste + adjust. Many people prefer to scale these to ~80–90% of the computed value first.

How to scale recipes like a pro

Scaling ingredients is the “math part,” but great cooking is also about technique. Use these quick rules to make scaled recipes turn out the way you expect.

• Scaling is usually linear: ingredients scale well.
• Use taste: season gradually, especially when scaling up.
• Pot size matters: larger batches need more stirring and heat management.

• Measure by weight if possible for consistent results.
• Pan size changes outcomes: bigger pans bake faster; thicker batter bakes slower.
• Leaveners can be sensitive: very large batch scaling may need small tweaks.

• Cook time often depends on thickness, not total weight—use a thermometer.
• More pieces can crowd the pan and slow browning—use larger trays or multiple trays.

• Post a “before → after” ingredient screenshot for a party meal.
• Use a hook: “I had to feed 13 people and didn’t want to do math…”
• Share the adjusted list directly in group chats.

Frequently Asked Questions

• Does this scale cooking time too?

  No—only ingredient amounts. Time and heat often change with batch size, thickness, pan type, and oven behavior. Use the scaled ingredients as your base, then cook to temperature/doneness.

• Why didn’t it scale one of my lines?

  The tool scales lines that start with a number (like “2 cups flour”). If a line begins with text (“Salt to taste”), it will be left unchanged. Put the quantity first if you want it scaled.

• Does it support fractions like 1 1/2?

  Yes. It supports decimals (1.5), fractions (3/4), mixed numbers (1 1/2), and ranges (2–3). You can also choose rounding to 1/8, 1/4, 1/2, or whole numbers.

• Is this accurate enough for baking?

  The math is accurate. For best baking results, use “No rounding” and weigh ingredients. If you round heavily, you may change hydration ratios in doughs/batters.

• Is my ingredient list sent anywhere?

  No. The calculation runs in your browser. If you save results, they’re stored locally on your device.