The Mix Iron Calculator adds up the iron contributed by every ingredient in a recipe or mixed dish. Enter the amount of each ingredient, choose grams or ounces, and provide the iron content per 100 g. The calculator converts everything to grams, totals the iron from all ingredients, and then shows the result per serving, per 100 g of the finished mix, and as a percentage of the Daily Value.
This tool is useful for meal planners who combine several iron-rich foods, people monitoring their iron intake for anemia or athletic performance, plant-based eaters building balanced plates, and dietitians checking recipes during nutrition consultations. Because the calculation uses your own ingredient iron values, it works for everything from a lunch bowl to a batch-cooked dinner.
Use the preset buttons to load a sample mix and explore how the totals change, or enter your own ingredients from a food label or nutrition database.
🥗 Build Your Iron Mix
Leave unused ingredient rows blank. Iron values are entered as mg per 100 g of that ingredient.
How to Use This Tool
Start by entering the ingredients in your mix. For each row, type an optional ingredient name, the amount used, and the iron content per 100 g. The amount unit can be grams or ounces; the calculator converts ounces to grams using 1 oz = 28.35 g. Iron content is usually printed on food labels as mg per 100 g, but you can also look up values in a nutrition database such as the USDA FoodData Central.
- Choose the serving size for the whole mix. If the recipe makes 4 portions, enter 4.
- Press Calculate Iron to see the total iron, total weight, iron per serving, iron per 100 g, and percentage of the Daily Value.
- Use the breakdown table to see which ingredient contributes the most iron.
You can leave unused ingredient rows blank; only completed rows are included in the calculation. If you change a portion size, simply edit the servings field and press Calculate again.
How the Mix Iron Calculation Works
The calculator uses three steps. First, each ingredient amount is converted to grams. If the unit is ounces, the amount is multiplied by 28.3495. Second, the iron contributed by each ingredient is calculated with this formula:
Ingredient iron (mg) = iron per 100 g × amount in grams ÷ 100
For example, 120 g of tofu with 5.4 mg iron per 100 g provides 120 × 5.4 ÷ 100 = 6.48 mg. All ingredient iron values are then added to give the total iron in the whole recipe. Total weight is the sum of all ingredient weights, since the calculator uses raw ingredient amounts rather than cooked weight loss or moisture changes.
The result per serving is simply total iron divided by the number of servings. Iron per 100 g of the mix is total iron divided by total weight multiplied by 100. The Daily Value percentage uses the FDA reference value of 18 mg of iron per day for adults and children aged four and older, so a result of 9 mg equals 50% of the Daily Value.
Worked Example: Spinach, Lentils & Quinoa Bowl
Imagine you are preparing a two-portion bowl with 100 g spinach (2.7 mg/100g), 80 g cooked lentils (3.3 mg/100g), and 150 g cooked quinoa (1.5 mg/100g).
Step 1: Spinach iron = 100 × 2.7 ÷ 100 = 2.70 mg.
Step 2: Lentil iron = 80 × 3.3 ÷ 100 = 2.64 mg.
Step 3: Quinoa iron = 150 × 1.5 ÷ 100 = 2.25 mg.
Total iron = 2.70 + 2.64 + 2.25 = 7.59 mg. Total weight = 330 g. Split between two servings, each portion provides 3.80 mg of iron, which is 21% of the Daily Value. The mix also has an iron density of 2.30 mg per 100 g.
Standard Iron Values for Common Mix Ingredients
When you do not have a package label, these approximate values (based on common USDA FoodData Central entries) can be used as a starting point for cooked or raw plant foods:
| Ingredient | Typical iron per 100 g |
|---|---|
| Cooked spinach | 3.6 mg |
| Cooked lentils | 3.3 mg |
| Firm tofu | 5.4 mg |
| Cooked quinoa | 1.5 mg |
| Lean ground beef (cooked) | 2.6 mg |
| Black beans (cooked) | 2.1 mg |
| Broccoli (cooked) | 0.5 mg |
| Fortified breakfast cereal | 8–28 mg |
Values vary by variety, cooking method, and brand, especially fortified products. For precise planning, check the nutrition facts panel or a regional food composition table.
Factors Affecting Iron Absorption and Accuracy
The calculator tells you how much iron is present in the food, but it does not predict how much iron your body absorbs. Heme iron from meat, poultry, and fish is absorbed more efficiently than non-heme iron from plants. Eating vitamin C-rich foods alongside a meal can improve non-heme iron absorption, while tannins in tea and coffee, calcium, and certain compounds in legumes can reduce it.
Accuracy is also affected by your ingredient values. Many nutrition databases report iron for raw foods, but cooking can change water content and therefore the iron concentration per 100 g. If you enter a value for raw spinach but weigh the cooked spinach, the estimate will be off. Use consistent weights: weigh the ingredient in the same state as the iron value you look up. For home-cooked mixed dishes, the calculated total is an estimate, not a laboratory analysis.
Frequently Asked Questions
Why do I need the iron value per 100 g?
Iron per 100 g is the standard way food labels and nutrition databases express micronutrients. It lets the calculator scale the amount you actually use. If your label shows a different serving size, convert it before entering: iron per 100 g = iron per serving × 100 ÷ serving size in grams.
Can I use this for a single ingredient?
Yes, just fill one row and leave the others blank. For faster single-food checks, you may prefer a dedicated single-item tool such as the eggplant iron calculator or the fennel iron calculator.
Should I use cooked or raw weights?
Use the weight that matches your iron value. Iron values for cooked vegetables and legumes usually refer to the cooked food as eaten. If your recipe lists raw pasta or rice, use the dry weight and the dry iron value. Consistency matters more than the choice itself.
What is a normal Daily Value target?
The FDA uses 18 mg as the Daily Value for iron for adults and children over four years. Individual requirements differ; for example, premenopausal women often need about 18 mg per day, while adult men might need around 8 mg. Your healthcare provider can give a personalized recommendation.