Fennel has a naturally low sodium profile, but how much you actually consume depends on portion size, how it is prepared, and whether salt is added during cooking. This calculator estimates the sodium content of fresh fennel bulb and boiled fennel bulb from any portion you enter, then compares it to your daily sodium target.
Use it to check a single serving, log a recipe, or compare a fennel side dish with higher-sodium packaged foods. Enter the amount, choose the unit, pick the fennel preparation, and the result gives you sodium in milligrams, the contribution to a 2,300 mg daily value, and a step-by-step breakdown so you always know how the number was calculated. Great for low-sodium diets, DASH meal planning, and anyone monitoring salt for heart health.
📊 Fennel Sodium Calculator
Estimate sodium in raw or boiled fennel portions.
How to Use This Tool
Start by entering the amount of fennel you plan to eat in the first field, then choose the unit that matches how you measure it. The calculator accepts grams, ounces, cups of sliced fennel, and whole medium bulbs. If you are tracking a recipe ingredient, grams or ounces are usually the easiest because they match most kitchen scales and nutrition labels.
Next, select whether your fennel is raw or boiled. The calculator uses a sodium value of 52 mg per 100 g for raw fennel bulb and 45 mg per 100 g for boiled fennel bulb that has been drained without added salt. Finally, set your daily sodium target. The default is 2,300 mg per day, which matches the FDA Daily Value, but you can change it to 1,500 mg if you follow the American Heart Association guideline or any other target your doctor recommends. Press Calculate to see the sodium in milligrams, the percentage of your daily target, and a quick breakdown of the math.
How the Sodium Calculation Works
Fennel is a low-sodium vegetable in its natural state. The USDA FoodData Central database reports that 100 grams of raw fennel bulb contains approximately 52 mg of sodium. Boiling bulb fennel without salt can reduce that to about 45 mg per 100 g because a small amount of sodium leaches into the cooking water, which is then discarded.
The calculator uses a simple proportional formula:
Sodium (mg) = portion weight in grams × (sodium density per 100 g ÷ 100)
For example, 150 g of raw fennel gives 150 × (52 ÷ 100) = 78 mg of sodium. To find the percent of your daily value, that result is divided by your sodium target and multiplied by 100. If your target is 2,300 mg, those 78 mg represent about 3.4% of the day’s allowance.
Worked Examples
Example 1: 100 g raw fennel. Weight = 100 g, sodium density = 52 mg/100 g. Sodium = 100 × 0.52 = 52 mg. Against a 2,300 mg target, that is 2.3% of the daily value. Against a 1,500 mg target, it is 3.5%.
Example 2: 1 cup sliced raw fennel. Weight = 87 g. Sodium = 87 × 0.52 = 45.2 mg. This is roughly 2.0% of a 2,300 mg daily allowance, making a cup of raw fennel an excellent choice for low-sodium meal plans.
Example 3: 1 medium bulb boiled fennel. Weight = 234 g, sodium density = 45 mg/100 g. Sodium = 234 × 0.45 = 105.3 mg. That equals 4.6% of the 2,300 mg Daily Value, still a very low-sodium portion even though the bulb is quite large.
Reference Data: Sodium in Fennel
| Fennel form | Sodium per 100 g | Typical portion | Sodium in that portion |
|---|---|---|---|
| Raw fennel bulb | 52 mg | 1 cup sliced (87 g) | ≈ 45 mg |
| Boiled fennel bulb, drained, no salt | 45 mg | 1 cup (87 g) | ≈ 39 mg |
| Raw fennel bulb | 52 mg | 1 medium bulb (234 g) | ≈ 122 mg |
| Boiled fennel bulb, drained, no salt | 45 mg | 1 medium bulb (234 g) | ≈ 105 mg |
Compare these numbers with common restaurant fennel dishes. A fennel gratin made with cheese or cream can easily exceed 400–600 mg of sodium per serving, and any dish seasoned with soy sauce or sea salt will be much higher. For a similar comparison tool, you can also estimate sodium in foods like falafel or curry on this site.
Tips and Common Mistakes
- Do not skip the preparation step. Raw and boiled fennel have slightly different sodium densities. The difference is small, but it can matter if you track sodium carefully or eat very large portions.
- Weigh raw fennel before cooking when possible. Fennel loses water as it cooks, so 100 g of boiled fennel is not the same as 100 g of raw fennel. If you measure after cooking, your sodium estimate will still be reasonable because the sodium density per 100 g already reflects the cooked form.
- Remember added salt. The calculator only estimates the natural sodium in fennel. If you add salt to the cooking water, sprinkle salt over the sliced bulb, or use a salted broth, those milligrams are separate. Tracking them separately keeps your sodium log accurate.
- Check fennel seeds separately. Dried fennel seeds have a much higher sodium density by weight, around 88 mg per 100 g, but you usually consume only a few grams at a time. A 1 g portion would contribute less than 1 mg of sodium, so seeds are rarely a concern unless you eat them by the spoonful.
- Do not confuse fennel with celery. Celery is often mentioned as a surprising source of sodium, and it is actually higher: about 80 mg per 100 g. Fennel is a milder, lower-sodium option for crunchy salads and slaws.
Frequently Asked Questions
Is fennel a low-sodium food? Yes. Raw fennel bulb contains about 52 mg of sodium per 100 g, which is roughly 2.3% of the 2,300 mg Daily Value. It is well suited to low-sodium diets, DASH eating patterns, and heart-healthy meal planning.
Why does boiled fennel have less sodium than raw fennel? When fennel is boiled in unsalted water, some of its natural minerals, including sodium, leach into the cooking water. If you drain the water away, the cooked fennel retains slightly less sodium. If you boil it in salted water, the opposite can happen: the vegetable can absorb some of the salt from the water.
Can I use this calculator for fennel seeds or fennel stalks? The calculator is designed for fennel bulb portions. Dried fennel seeds have a different sodium density per 100 g, and fennel stalks are not typically eaten in enough quantity to matter. For seed-based sodium estimates, weigh a small amount in grams and multiply by 0.88 mg/g.
What is the best daily sodium target for me? The FDA uses 2,300 mg per day as the general Daily Value for sodium. The American Heart Association recommends an ideal limit of no more than 1,500 mg per day for most adults, especially those with high blood pressure. Your doctor or dietitian can give you a personalized target based on your health history.