Fennel is a crisp, aromatic vegetable prized for its mild licorice flavor and impressive nutritional profile. Whether you’re tracking calories for weight management, meal prepping, or simply curious about the macros in your fennel salad or roasted side dish, this calculator gives you an instant breakdown of calories, carbohydrates, fiber, protein, and fat based on the amount you plan to eat.
Designed for home cooks, dietitians, and health-conscious eaters, the tool supports multiple units — grams, ounces, cups (sliced), and medium bulbs — so you can enter your portion exactly as you measure it. The results include a full macronutrient split plus a step-by-step explanation of how each value is derived from standard USDA nutrition data for raw fennel bulb. Use it to plan balanced meals, log your intake accurately, or compare fennel to other low-calorie vegetables.
🧮 Fennel Calorie & Macro Calculator
📊 Step-by-Step Breakdown
Enter an amount and click Calculate.
How to Use This Tool
Using the Fennel Calorie Calculator is straightforward. Start by entering the amount of fennel you plan to eat — you can type any positive number in the input field. Then select the unit that matches how you measure your fennel: grams (g), ounces (oz), cups of sliced fennel, or whole medium bulbs. For quick reference, click one of the preset buttons (e.g., "85 g (3 oz)" or "1 cup sliced") to auto-fill common portions. Press the blue Calculate button to see the calorie and macronutrient breakdown. The results show calories, carbohydrates, fiber, protein, and fat, each rounded to one decimal place. Below the main results, a step-by-step breakdown explains how each value was derived from the USDA reference data for raw fennel bulb. Use the Reset button to clear all fields and start a new calculation.
Formula Explained
The calculator uses standard USDA nutrition data for raw fennel bulb (Foeniculum vulgare) per 100 grams. The base values are:
- Calories: 31 kcal
- Carbohydrates: 7.3 g
- Fiber: 3.1 g
- Protein: 1.24 g
- Fat: 0.2 g
When you enter an amount in any supported unit, the tool first converts it to grams using these conversion factors:
- 1 ounce = 28.3495 g
- 1 cup sliced fennel = 87 g
- 1 medium bulb = 234 g
Then each nutrient value is multiplied by the ratio of your portion's weight to 100 g. For example, if you enter 150 g of fennel, the factor is 150 ÷ 100 = 1.5, so calories = 31 × 1.5 = 46.5 kcal. The same factor applies to carbs, fiber, protein, and fat.
Worked Examples
Example 1: You want to know the calories in 1 cup of sliced fennel (87 g). Enter 87 in the amount field, select "cups (sliced)" as the unit, and click Calculate. The result shows 27.0 kcal, 6.4 g carbs, 2.7 g fiber, 1.1 g protein, and 0.2 g fat.
Example 2: You have a medium fennel bulb weighing about 234 g. Select "medium bulbs" and enter 1. The calculator returns 72.5 kcal, 17.1 g carbs, 7.3 g fiber, 2.9 g protein, and 0.5 g fat. This is a typical serving for a roasted fennel side dish.
Example 3: You're logging 3 oz (85 g) of raw fennel in a salad. Click the "85 g (3 oz)" preset button. The results: 26.4 kcal, 6.2 g carbs, 2.6 g fiber, 1.1 g protein, and 0.2 g fat.
Tips for Accurate Tracking
For the most precise results, weigh your fennel on a kitchen scale in grams rather than relying on volume or piece counts. The weight of a "medium bulb" can vary from 200 g to 300 g depending on variety and freshness. If your bulb is noticeably larger or smaller, adjust the amount accordingly. When measuring sliced fennel by the cup, pack it loosely — a tightly packed cup can weigh significantly more than 87 g, which would increase the calorie count. The USDA data used here is for raw fennel bulb; cooking methods (roasting, sautéing) may add oil or butter that changes the final calorie content. Always account for added fats separately.
Frequently Asked Questions
Is fennel low in calories? Yes, fennel is very low in calories — only 31 kcal per 100 g — making it an excellent choice for weight management and low-calorie diets.
Does fennel contain much fiber? Fennel provides 3.1 g of fiber per 100 g, which is a good amount for a vegetable. Fiber aids digestion and helps you feel full longer.
Can I use this calculator for cooked fennel? The data is based on raw fennel bulb. Cooking can cause water loss, concentrating nutrients slightly, but the difference is usually small. For best accuracy, weigh fennel raw before cooking.
What about fennel seeds or fennel tea? This calculator is designed for the fresh bulb only. Fennel seeds have a very different nutritional profile (higher in calories and fat), and fennel tea is essentially calorie-free.
Where does the nutrition data come from? The values are sourced from the USDA FoodData Central database, which is the standard reference for food composition in the United States. You can look up the full entry for raw fennel bulb (NDB number 11957) on the USDA FoodData Central website.