How the Recipe Scaler Works

Tóm tắt

The Recipe Scaler adjusts ingredient quantities when you need more or fewer servings than a recipe makes. Enter your recipe’s ingredients with gram weights, set the original and target serving counts, and see scaled amounts instantly — along with per-serving and total nutritional information from the USDA FoodData Central database.

Cách hoạt động

1. Add ingredients — search the 142-food USDA database and add foods to your recipe with gram weights per total recipe.
2. Set servings — enter how many servings the original recipe makes and how many you want.
3. See scaled amounts — every ingredient is multiplied by the scale factor. Nutritional totals (calories, macros) update live for both the total recipe and per serving.

The scaling formula

The ratio target_servings ÷ original_servings is the scale factor. If a recipe makes 4 servings and you want 6, the scale factor is 1.5 — every ingredient is multiplied by 1.5.

Nutritional calculation

All nutrient values in the database are stored per 100g. To calculate nutrients for a given portion:

Total recipe nutrition is the sum of all scaled ingredient values. Per-serving nutrition divides the total by the target serving count.

Macro energy percentages

The protein/carbs/fat energy split uses the Atwater general factors — the standard system for food energy labelling (EU Regulation 1169/2011, FAO):

Ví dụ minh họa

A chicken stir-fry recipe makes 4 servings. You want 6 servings (scale factor = 1.5).

Original recipe: 400g chicken breast + 600g brown rice (cooked) + 200g broccoli.

Macro energy split (per serving, Atwater 4-4-9):

• Protein: 28.0 × 4 = 111.8 kcal → 35.2%
• Carbs: 41.7 × 4 = 166.8 kcal → 52.6%
• Fat: 4.3 × 9 = 38.7 kcal → 12.2%

Giải thích đầu vào

• Recipe makes (servings) — how many servings the original recipe produces. Default: 4.
• I want (servings) — how many servings you need. Quick-select buttons for common counts (1, 2, 4, 6, 8, 12).
• Ingredients — search and add foods from the USDA database. Enter the gram weight per total recipe (not per serving).

Giải thích đầu ra

• Scale factor — shown when target differs from original (e.g. “1.5× scaling up”).
• Ingredient table — original and scaled gram weights side by side.
• Per serving nutrition — calories (hero number), protein, carbs, fat, fiber with macro energy percentages.
• Total recipe nutrition — summed across all ingredients for the full scaled recipe.

Giả định và hạn chế

• Linear scaling — all ingredients scale proportionally by the same factor. This is mathematically exact but may not suit all recipes: seasoning and spices often need less-than-proportional increases, and baking recipes with yeast or leavening agents may not scale well beyond 2–3×.
• Gram weights only — the calculator works in grams for precision. Volume measures (cups, tablespoons) are not supported because they vary by ingredient density.
• USDA data — nutrient values are for generic foods, not branded products. Actual values vary by growing conditions, cooking method, and brand.
• Raw vs cooked — select the form matching how you measure the ingredient. 100g raw chicken ≠ 100g cooked chicken in nutritional content.
• 142 foods — the database covers common whole foods. Processed, branded, and restaurant foods are not included.
• No cooking losses — the calculator does not account for moisture loss, fat rendering, or nutrient degradation during cooking. Scaled weights are pre-cooking weights.

Xác minh