Peanuts are a popular, nutrient-dense snack, but their iron content can vary significantly depending on the form you choose — raw, dry-roasted, oil-roasted, or as peanut butter. This calculator helps you quickly estimate the iron (mg) and % Daily Value (%DV) for any serving size of peanuts or peanut products, based on USDA reference data.
Whether you're tracking micronutrients for a plant-based diet, managing iron intake for health reasons, or simply curious about the nutritional profile of your favorite nut, this tool provides accurate, instant results. Use it to compare different peanut types, plan meals, or log your daily iron consumption with confidence.
🥜 Peanut Iron Calculator
📊 Results
How to Use This Tool
Select the peanut type from the dropdown — raw, dry-roasted, oil-roasted, or peanut butter. Enter your serving size (grams, ounces, cups, or tablespoons) and click "Calculate Iron". The tool instantly shows the iron content in milligrams and the % Daily Value based on the FDA reference of 18 mg per day for adults. Use the preset buttons for common serving sizes like 1 oz or 1 tablespoon of peanut butter.
💡 Tip: For the most accurate results, weigh your peanuts on a kitchen scale. Volume measurements (cups, tablespoons) are estimates — actual density can vary by how tightly the peanuts are packed.
Iron Content Reference Table
The table below shows the iron content per 100 grams for each peanut type, based on USDA FoodData Central data.
| Peanut Type | Iron per 100g (mg) | % DV per 100g |
|---|---|---|
| Raw Peanuts | 4.58 | 25.4% |
| Dry-Roasted Peanuts | 4.58 | 25.4% |
| Oil-Roasted Peanuts | 2.20 | 12.2% |
| Peanut Butter (smooth) | 2.10 | 11.7% |
How It Works
The calculator uses USDA reference values for iron per 100 grams of each peanut type. It converts your serving size to grams using standard density factors (1 oz = 28.35 g, 1 cup of peanuts ≈ 146 g, 1 tbsp peanut butter ≈ 16 g). Then it applies the formula: Iron (mg) = (Iron per 100g × Serving in grams) ÷ 100. The % Daily Value is calculated by dividing the result by 18 mg (the adult daily value for iron) and multiplying by 100.
Example: You eat 2 tablespoons of peanut butter (32 g). Iron per 100g of peanut butter = 2.10 mg. Iron = (2.10 × 32) ÷ 100 = 0.67 mg. % DV = (0.67 ÷ 18) × 100 = 3.7%. So 2 tbsp of peanut butter provides about 3.7% of your daily iron needs.
Factors Affecting Iron Absorption
Peanuts contain non-heme iron, which is less readily absorbed than the heme iron found in meat. Absorption can be enhanced by consuming vitamin C-rich foods (like citrus fruits, bell peppers, or tomatoes) alongside peanuts. Tannins in tea and coffee can inhibit absorption, so consider spacing your peanut snack away from these beverages. For individuals following a plant-based diet, pairing peanuts with other iron sources like leafy greens or legumes can help meet daily requirements.
Frequently Asked Questions
Are peanuts a good source of iron? Yes — raw and dry-roasted peanuts provide about 4.58 mg per 100g, which is over 25% of the daily value. However, oil-roasted peanuts and peanut butter have lower iron content (around 2.1 mg per 100g) due to processing and added oils.
Why do oil-roasted peanuts have less iron? The roasting process with oil can dilute the iron concentration, and some iron may be lost during processing. Always check the label for added ingredients.
Can I use this calculator for other nuts? This tool is specifically calibrated for peanuts. For other nuts, try our coffee iron calculator or guacamole iron calculator for different foods.
Is the % DV based on a specific diet? The 18 mg daily value is the FDA reference for adults and children aged 4 years and older. Individual needs may vary — pregnant women, for example, require 27 mg per day.
Real-World Applications
This calculator is useful for dietitians planning iron-rich meals for clients, athletes tracking micronutrient intake, vegetarians and vegans monitoring their iron status, and anyone using food tracking apps who wants to verify their entries. Peanuts are a convenient, shelf-stable snack that can contribute meaningfully to daily iron goals, especially when combined with other iron-rich plant foods.