How to work out a recipe’s macros from its ingredients
A step-by-step method for estimating calories, protein, carbs and fat for a home recipe from the ingredient amounts, and where the estimate can go wrong.
Recipe videos almost never come with nutrition facts. You can estimate them yourself from the ingredients, and it’s more accurate than guessing from the finished dish.
The method
- Write down each ingredient with its amount, converted to grams where you can.
- Look each ingredient up in a nutrition database such as USDA FoodData Central, using the closest match (raw versus cooked matters).
- Multiply the per-100 g values by the grams you used.
- Add everything up for the whole recipe.
- Divide by the number of servings.
Where the estimate goes wrong
- Missing amounts. “A drizzle of oil” can be 40 calories or 200. Leave it out and say so, or measure it next time.
- Oil left in the pan and fat you drain off aren’t eaten, but they’re counted.
- Raw versus cooked weights differ a lot for pasta, rice and meat.
- Unclear servings. If the video doesn’t say how many it serves, a per-serving number is a guess. Use whole-recipe totals instead.
How the app does it
Recipe from Video matches each ingredient with an amount to a row in a bundled copy of the USDA SR Legacy table, then the code does the arithmetic, not the AI model. You see which ingredients were counted and which weren’t, and when a video doesn’t give servings you get whole-recipe totals. Treat the result as an estimate, not a label.
