Mushrooms are a surprising source of iron among plant foods. While they are not as concentrated as red meat or legumes, certain varieties — especially morels, oyster mushrooms, and shiitake — can make a meaningful contribution to your daily iron intake, especially when paired with vitamin C.
This mushroom iron calculator lets you estimate the iron content of a specific portion of mushrooms in seconds. Choose a mushroom variety, enter your portion size in grams or ounces, and the tool calculates the milligrams of iron and its percentage of the recommended Daily Value. It’s useful for meal planning, plant-based eating, fitness tracking, and anyone curious about micronutrient intake.
All calculations are based on standard USDA food composition values for raw and cooked mushrooms. Use the results as a practical guide, not a laboratory measurement.
How to Use This Mushroom Iron Calculator
Start by choosing the mushroom variety that best matches what you plan to eat. The dropdown includes common fresh mushrooms — white button, brown/cremini, portobello, oyster, shiitake, enoki, and morel — with their typical iron content per 100 g. If your food is not listed, choose the closest relative: for example, use white button for other small cultivated mushrooms.
Next, enter your portion size in grams or ounces. A kitchen scale gives the most reliable number, but you can also use common portion estimates: about 70 g of sliced raw mushrooms is roughly one cup, 85 g equals 3 ounces, and a large portobello cap weighs about 100 g. The quick-pick buttons can fill these values automatically.
Press Calculate Iron to see the estimated iron in milligrams and the percentage of the adult Daily Value. Press Reset to clear the result and start a new entry.
Tip: If you already know the cooked weight of your mushrooms, use that weight with a cooked variety option. Cooking removes water, so 100 g of cooked mushrooms contains more mushroom solids per gram than 100 g of raw mushrooms — this is why cooked values sometimes look higher per 100 g.
How Mushroom Iron Is Calculated
The tool uses a simple proportion based on USDA food composition data. Each variety in the list has an average iron value per 100 g of edible raw or cooked mushroom. The calculation is:
Iron (mg) = (Portion weight in grams ÷ 100) × Iron per 100 g
After finding the iron mass, the tool converts it to a percentage of the Daily Value. The FDA uses 18 mg as the Daily Value for iron for adults and children over four years, so:
% Daily Value = (Iron mg ÷ 18) × 100
Example: You eat 120 g of raw oyster mushrooms. With 1.3 mg iron per 100 g, the calculation is (120 ÷ 100) × 1.3 = 1.56 mg. Divide by 18 and multiply by 100 to get 8.7% of the Daily Value. That is a useful contribution, though most of the iron in mushrooms is non-heme iron, which is absorbed less efficiently than the heme iron in meat.
Iron Content Reference Table
These values are typical averages drawn from USDA food composition databases. Actual iron content can vary with growing substrate, maturity, and analytical batch.
| Mushroom variety | Preparation | Iron per 100 g |
|---|---|---|
| White button | Raw | 0.5 mg |
| Brown / cremini | Raw | 0.4 mg |
| Portobello | Raw | 0.3 mg |
| Oyster | Raw | 1.3 mg |
| Shiitake | Cooked | 0.5 mg |
| Enoki | Raw | 1.0 mg |
| Morel | Raw | 12.2 mg |
Sources: USDA FoodData Central (fdc.nal.usda.gov) and the NIH Office of Dietary Supplements (Iron Fact Sheet).
Factors That Affect Actual Iron Content
Mushrooms absorb minerals from their growing substrate, so iron levels can be higher or lower than the averages in the table depending on soil, compost, water, and whether the product is wild-foraged or cultivated. Morels, for instance, are often collected from forest soil that is rich in organic matter, which may explain their unusually high iron concentration.
Cooking method also matters. Frying adds fat but does not meaningfully change iron; boiling can leach some minerals into the cooking water; and drying concentrates iron per gram by removing water. If you weigh mushrooms after cooking, remember that the weight includes less water, so the iron density per 100 g increases even though the total iron in the original piece of food stays roughly the same.
Not a medical tool: This calculator provides dietary estimates, not medical advice. If you have iron-deficiency anemia, hemochromatosis, or other conditions that affect iron balance, talk to a healthcare provider before making major changes to your diet.
Practical Tips for Getting More Iron From Mushrooms
Because mushroom iron is mostly non-heme iron, its absorption can vary. Pair mushrooms with vitamin C-rich foods such as roasted red peppers, broccoli, lemon juice, tomatoes, or citrus salsa to help your body absorb more of the iron. Avoid drinking coffee or tea immediately with the meal, since tannins and polyphenols can reduce iron absorption; waiting an hour is a simple workaround.
Mushrooms also deserve attention in plant-based meal plans for their savory flavor and texture. Adding morel or oyster mushrooms to pasta, stir-fries, soups, and risotto increases both zinc and iron intakes. For a more concentrated source, dried shiitake and dried morel can be rehydrated and added to broths; just remember to account for the dried weight if you are tracking nutrients.
Meal idea: Sauté oyster mushrooms with spinach, red bell pepper, and garlic, and squeeze lemon over the finished dish. This combines a moderate-iron mushroom with vitamin C and an additional plant iron source from spinach.
Frequently Asked Questions
Which mushroom has the most iron?
Among the varieties in this calculator, raw morel mushrooms have the highest average iron content at about 12.2 mg per 100 g. Oyster and enoki are next at roughly 1.0–1.3 mg per 100 g. White button, cremini, and portobello are lower.
Is mushroom iron absorbed as well as meat iron?
No. Mushrooms provide non-heme iron, the same type found in plants. Non-heme iron absorption is typically lower than heme iron from meat, but it improves when eaten with vitamin C and can be reduced by tannins in tea and coffee. This is why pairing foods matters.
Can mushrooms help with anemia?
They can contribute to iron intake, especially morel and oyster varieties, but they are not a dense iron source compared with beef liver, lentils, or fortified cereals. For iron deficiency, focus on a varied diet and follow medical guidance.
Why does the calculator show one value per variety?
The calculator uses a single average value per variety. The table and notes highlight that real-world values can vary. If you want a more precise number, look for the specific product label or USDA entry for the exact cultivar and preparation.
For another mushroom micronutrient check, try the mushroom vitamin C calculator or compare iron in grain-based snacks with the pretzel iron calculator.