Yams are starchy, nutrient-dense root vegetables grown throughout Africa, Asia, and the Caribbean. Unlike sweet potatoes, true yams belong to the Dioscorea genus and provide a hearty source of complex carbohydrates, fiber, and potassium. This calculator uses USDA nutrition data for both raw and boiled or baked yams so you can estimate calories and key nutrients for any serving.
Enter your serving size in grams, ounces, cups of cubed yam, or whole medium yams. Choose whether the yam is raw or cooked, then hit Calculate to see calories, protein, carbs, fat, fiber, sugar, and an optional breakdown of micronutrients such as vitamin C, vitamin B6, magnesium, and folate.
The tool is designed for home cooks, meal preppers, and anyone tracking macros. If you are building a balanced plate, pair the result with other foods in your meal to get the full picture of your daily intake.
🥢 Serving Size
🍳 Preparation
📊 Nutrition Estimate
- Potassium: — mg
- Vitamin C: — mg
- Vitamin B6: — mg
- Magnesium: — mg
- Folate: — µg
How to Use This Tool
Start by entering the amount you plan to eat — the calculator accepts grams, ounces, cups of cubed yam, or whole medium yams. If you are logging a recipe, the cup option is convenient, but remember that cube size changes how much flesh actually fits in a cup; the tool assumes a standard 150 g per cup of medium cubes. Next, choose whether your yam is raw or boiled/baked. Raw values describe peeled, uncooked flesh, while cooked values reflect yams boiled or baked without added fat. Leave the micronutrient box checked if you want the full panel of potassium, vitamin C, vitamin B6, magnesium, and folate, then press Calculate Nutrition.
Tip: one medium yam is roughly 200 g after peeling, and about 95 g of that is typically edible flesh after trimming. Weighing in grams gives the most consistent results; cup estimates vary with cube size and how firmly you pack the cup.
The Math Behind It
The calculator is built on USDA FoodData Central values for true yams (Dioscorea spp.). Every nutrient is expressed per 100 g of edible flesh, so the tool converts your chosen unit into grams first: 1 oz = 28.3495 g, 1 cup of cubed yam ≈ 150 g, and 1 medium yam ≈ 200 g. It then applies a simple multiplier of serving grams ÷ 100 to every value.
For example, a 250 g portion of boiled yam uses a factor of 2.5. With cooked values of 116 kcal per 100 g, that portion delivers about 290 kcal. The same logic scales protein, carbohydrates, fiber, sugar, and each micronutrient. Note that cooking affects some nutrients: boiling leaches a small amount of potassium into the water and degrades some vitamin C and vitamin B6, which is why the raw and cooked reference values differ slightly. For the full official dataset, see USDA FoodData Central.
Worked Examples
Example 1 — tracking by cup: You eat 1.5 cups of boiled cubed yam. At 150 g per cup, that equals 225 g, so the multiplier is 2.25. Using cooked values per 100 g (116 kcal, 1.49 g protein, 27.88 g carbs, 4.1 g fiber), the result is about 261 kcal, 3.4 g protein, 63 g carbs, and 9 g fiber.
Example 2 — tracking by weight: A home cook roasts 400 g of raw yam for a family meal. The raw data give 118 kcal per 100 g, so the factor is 4.0. That serving provides roughly 472 kcal, 6.1 g protein, 112 g carbs, and 16 g fiber — a substantial carbohydrate portion best paired with protein and vegetables.
Reference Data — USDA Values per 100 g
The table below summarizes the values used in this calculator. Consult it when you want to compare a 100 g portion of raw versus cooked yam at a glance.
| Nutrient | Raw yam (100 g) | Boiled / baked yam (100 g) |
|---|---|---|
| Calories | 118 kcal | 116 kcal |
| Protein | 1.53 g | 1.49 g |
| Carbohydrates | 27.88 g | 27.88 g |
| Fat | 0.17 g | 0.14 g |
| Fiber | 4.1 g | 4.1 g |
| Sugars | 0.5 g | 0.5 g |
| Potassium | 816 mg | 670 mg |
| Vitamin C | 17.1 mg | 12.1 mg |
| Vitamin B6 | 0.293 mg | 0.223 mg |
| Magnesium | 21 mg | 14 mg |
| Folate | 23 µg | 23 µg |
Common Mistakes to Avoid
Confusing yams with sweet potatoes. In many U.S. grocery stores, moist orange sweet potatoes are mislabeled as "yams." They are a different species with very different nutrition — sweet potatoes are much higher in vitamin A. This calculator reflects true yams (Dioscorea species) only.
Logging the whole tuber. The peel, trimmings, and bruised ends are not edible flesh. If a raw yam weighs 400 g on the scale, the edible portion is usually closer to 330–350 g. Always enter the weight of the flesh you actually eat.
Tip: If your yam is roasted in oil or butter, add a few grams of fat to your meal log — the calculator assumes no added fat for boiled or baked preparations.
Frequently Asked Questions
Are yams a good source of vitamin A? No. True yams are nearly devoid of beta-carotene, providing negligible vitamin A. If you are looking for vitamin A, an orange sweet potato is a far better choice.
Why does the potassium value drop after cooking? Boiling causes water-soluble minerals to leach into the cooking water. Baking without water retains more potassium, but the USDA cooked reference still reflects a blended average of cooking methods. For precise potassium tracking, weigh your yam raw and use the raw values.
Can I use this for African or Asian yam varieties? Yes. Varieties such as white yam, yellow yam, and water yam differ slightly in moisture and starch, but the USDA reference values used here are representative of the genus as a whole.