Yams are a starchy root vegetable featured in African, Caribbean, Asian, and South American cuisines. Although they are not as famous for fiber as beans or oats, yams deliver a surprisingly solid amount of insoluble fiber — about 4.1 g per 100 g when raw and 3.9 g when cooked. This calculator shows exactly how much fiber you get from any yam serving, expressed in grams, ounces, and as a percentage of your daily fiber goal.
Enter your serving size, pick grams, ounces, or pounds, then choose whether the yam is raw or cooked. The tool converts your portion into grams, applies the standard fiber value, and lays out every step of the math. It is ideal for meal planning, macronutrient tracking, checking your fiber intake, or comparing yams with other starchy staples. No signup is required — enter a number, press calculate, and get a reliable estimate in seconds.
🍠 Yam Fiber Per 100g Calculator
Estimate the fiber in any yam serving, with a daily value breakdown.
How to Use This Tool
Start by entering the amount of yam you plan to eat, then choose the matching unit from the dropdown — grams, ounces, or pounds. The calculator automatically converts your portion to grams, so the unit you pick does not affect the accuracy of the result. Next, tell the tool whether the yam is raw or cooked, because the two forms have slightly different fiber densities: raw yam contains about 4.1 g of fiber per 100 g, while cooked yam contains about 3.9 g per 100 g. The optional daily fiber goal is pre-set to 28 g, the Daily Value used on a 2,000-calorie diet, but you can change it to match your personal target if you track fiber intake for health, weight management, or digestion.
When you press "Calculate fiber," the tool shows the total fiber in grams and ounces, the fiber per 100 g for your selected preparation, and the percentage of your daily goal the serving covers. A short three-step breakdown explains exactly how the numbers were derived. The quick-fill buttons below the serving input are useful shortcuts: "1 cup cubed" applies a 150 g portion of raw yam cubes, and "1 medium yam" applies an 180 g portion, which is a typical peeled yam serving.
Tip: Weigh the yam raw if you select the raw option, and cooked if you select the cooked option. Cooking adds water weight, so fiber per 100 g is slightly lower for cooked yam even though the total fiber in a specific piece stays the same before and after cooking.
Formula Explained
The calculation runs in two steps. First, the serving weight is converted to grams using fixed conversion factors: 1 ounce = 28.3495 g and 1 pound = 453.592 g. Second, the fiber density of the selected preparation is applied:
Fiber (g) = serving weight (g) × fiber per 100 g ÷ 100
Raw yam is set to 4.1 g of fiber per 100 g and cooked yam to 3.9 g per 100 g, based on USDA FoodData Central values for yam, raw and yam, cooked, boiled or baked without salt. For the daily value, the tool divides the fiber result by your goal: Daily value % = fiber (g) ÷ goal (g) × 100.
Why does the fiber density change with cooking? Boiling or roasting introduces water into the flesh, so 100 g of cooked yam contains more water and slightly less dry matter than 100 g of raw yam. Fiber itself is not destroyed by normal cooking, but it becomes more dilute per gram of cooked product. Weighing your portion in the same state you select in the tool is therefore the key to an accurate estimate.
Worked Examples
Example 1 — Cooked yam, metric portion. Suppose you eat a 200 g serving of roasted yam (cooked). Fiber = 200 × 3.9 ÷ 100 = 7.8 g. Against the default 28 g daily goal, that single serving covers 7.8 ÷ 28 = 27.9% of the recommended daily fiber intake. In ounces, 7.8 g × 0.035274 = 0.28 oz.
Example 2 — Raw yam, imperial portion. A recipe calls for 8 oz of raw yam. Convert to grams: 8 × 28.3495 = 226.8 g. Fiber = 226.8 × 4.1 ÷ 100 = 9.30 g. If your daily fiber target is 30 g, this portion covers 9.30 ÷ 30 = 31.0% of your goal — roughly a third of the day's fiber budget from one starchy side dish.
Tips & Common Mistakes to Avoid
Be consistent about which state you weigh. The most common error is weighing a cooked portion but selecting the raw fiber value, which overestimates fiber by about 5%. Another frequent mistake is misunderstanding the difference between yams and sweet potatoes: in many grocery stores the label says "yam," but true yams (Dioscorea species) are a different plant from sweet potatoes (Ipomoea batatas), and their fiber values differ. If you are actually eating a sweet potato, use a sweet potato calculator instead for a more accurate result.
Also remember that these values apply to peeled flesh. Yam skin is thick, woody, and normally removed before cooking, so do not include its weight in your serving. Finally, if you are tracking fiber for blood sugar management or digestion, note that yam fiber is mostly insoluble — it supports regularity but is less effective at softening stools than soluble fiber like that from oats or psyllium.
Standard Fiber Values
The table below summarizes common yam portions and their fiber content using the same USDA data the calculator applies.
| Yam form | Serving | Fiber |
|---|---|---|
| Raw yam | 100 g | 4.1 g |
| Cooked yam | 100 g | 3.9 g |
| Raw yam | 1 cup cubes (150 g) | 6.2 g |
| Cooked yam | 1 cup cubes (136 g) | 5.3 g |
| Cooked yam | 1 medium yam (180 g) | 7.0 g |
Frequently Asked Questions
Are yams the same as sweet potatoes? No. Yams (Dioscorea species) and sweet potatoes (Ipomoea batatas) are different plants with different nutritional profiles. Raw yam has about 4.1 g of fiber per 100 g, while raw sweet potato has about 3.3 g — both are good starchy choices, but the numbers are not interchangeable.
Why does cooked yam show less fiber per 100 g? Cooking adds water, so 100 g of cooked yam contains more water and slightly less dry matter than 100 g of raw yam. If you weigh your yam after cooking, the cooked value is the more accurate one to use.
Should I peel the yam before weighing? Yes. These values apply to peeled flesh. Yam skin is thick, fibrous, and typically removed before cooking or eating.
What if I do not know my daily fiber goal? The 28 g default is the Daily Value for fiber on a 2,000-calorie diet in the United States. Many nutrition organizations recommend 25–38 g per day for adults, so you can adjust the goal field to your own target — 25 g for many women and 38 g for many men is a common starting point.
Reference data from USDA FoodData Central.