How Much Fiber in a Sweet Potato? Amounts by Size, Skin, and Prep
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If you are asking how much fiber in sweet potato you actually get, the short answer is about 4 grams in one medium sweet potato eaten with the skin on, which is roughly 3 to 3.5 grams per 100 grams of cooked flesh. Size is the biggest variable, so a small sweet potato lands closer to 2 grams and a large one can push past 6 grams.
That puts a medium sweet potato at roughly 14 percent of the 28 gram Daily Value for fiber, which is a solid contribution from a single vegetable. Below is how the number shifts based on size, skin, variety, and how the potato was prepared.
Sweet Potato Fiber by Size
Produce is not standardized, and that is why fiber numbers online look inconsistent. A "medium" sweet potato at one grocery store can weigh twice what another store calls medium. Weight is the honest way to estimate.
| Size | Approximate weight | Fiber (with skin) | Percent of 28g DV |
|---|---|---|---|
| Small | 60 to 80 g | About 2 g | About 7% |
| Medium | 115 to 130 g | About 4 g | About 14% |
| Large | 180 to 200 g | About 6 g | About 21% |
| 1 cup, cubed and cooked | About 200 g | About 6.5 g | About 23% |
| 1 cup, mashed | About 255 g | About 8 g | About 29% |
Mashed reads highest simply because a cup of mash packs more sweet potato by weight than a cup of loose cubes. The food did not change, only the density.
How Much of That Fiber Is in the Skin
The skin is concentrated fiber, but it is a small share of the total mass, so peeling costs you less than people assume. A medium sweet potato eaten with the skin gives you roughly 4 grams. Peel it and you are looking at closer to 3 to 3.3 grams. That is a loss of around 15 to 20 percent, not half.
Still, the skin is free fiber with no extra calories and no extra prep, so leaving it on is an easy win. If you want the full breakdown on texture, washing, and whether the peel is worth eating, see our guide to sweet potato skin.
Does Cooking Change the Fiber Content
Fiber is structurally stable. Heat does not destroy it the way it can degrade certain vitamins, so a cooked sweet potato has essentially the same fiber as the raw one it came from. What changes is water content and therefore the per-gram math.
- Baking and roasting drive off moisture, so the cooked potato weighs less and reads slightly higher in fiber per 100 grams.
- Boiling adds water weight, which dilutes the per-gram number even though the whole potato still holds the same total fiber.
- Drying removes the most water of all, which is why dried sweet potato reads high in fiber per ounce.
- Frying adds fat and calories without adding fiber, so the ratio of fiber to calories drops.
The practical takeaway is that one whole medium sweet potato delivers about 4 grams of fiber no matter which method you use. Only the label math moves.
Fiber by Variety
Different sweet potatoes land in a fairly narrow band, but there are real differences. Drier, starchier varieties tend to test a bit higher per 100 grams because they carry less water.
| Variety | Flesh | Approx. fiber per 100 g cooked |
|---|---|---|
| Orange (Beauregard, Jewel) | Moist, soft | About 3.3 g |
| Japanese (Satsumaimo) | Dry, dense, pale yellow | About 3.5 to 4 g |
| Korean (Goguma) | Dense and sweet | About 3.5 g |
| Purple | Firm, starchy | About 3.5 to 4 g |
| White | Crumbly, mild | About 3 g |
These gaps are small enough that variety should be a flavor and texture decision, not a fiber decision. If you are comparing types, our overview of types of sweet potatoes walks through each one.
How Sweet Potato Fiber Compares to Other Foods
Context helps. Most adults in the United States fall short of the recommended 25 to 38 grams of fiber per day, so it is useful to know where a sweet potato sits among common options.
| Food | Serving | Approximate fiber |
|---|---|---|
| Sweet potato, with skin | 1 medium | 4 g |
| Russet potato, with skin | 1 medium | 4 g |
| Banana | 1 medium | 3 g |
| Apple, with skin | 1 medium | 4.5 g |
| Black beans | 1/2 cup cooked | 7.5 g |
| Broccoli | 1 cup cooked | 5 g |
| Brown rice | 1 cup cooked | 3.5 g |
Sweet potato is a strong everyday contributor rather than a fiber powerhouse. Beans and lentils will always outrank it. Where sweet potato wins is versatility, since it shows up at breakfast, in bowls, and as a snack. For how fiber sits alongside carbs, protein, and fat, see our breakdown of sweet potato macros.
Getting More Fiber From Sweet Potato Without Trying Harder
A few small habits move the number more than switching varieties ever will.
- Leave the skin on when the texture works for the dish.
- Choose larger sweet potatoes when fiber is the goal, since size drives the total.
- Pair sweet potato with beans, greens, or seeds so the meal stacks fiber from multiple sources.
- Reach for a dried sweet potato snack between meals instead of a low fiber option.
- Spread fiber across the day rather than loading it into one sitting.
If you are increasing fiber for a specific health or nutrition goal, talk with your doctor or a registered dietitian about the right target and pace for you.
Frequently Asked Questions
How much fiber is in one medium sweet potato?
About 4 grams with the skin on, and roughly 3 to 3.3 grams peeled. That assumes a medium potato weighing 115 to 130 grams. Heavier potatoes carry proportionally more.
Is a sweet potato a high fiber food?
It qualifies as a good source rather than a high source under standard labeling conventions, which generally reserve "high" for foods delivering 20 percent or more of the Daily Value per serving. A medium sweet potato lands around 14 percent, and a large one gets close to 20 percent.
Do sweet potatoes have more fiber than regular potatoes?
They are close. Eaten with skin, both a medium sweet potato and a medium russet land near 4 grams. The bigger differences between them show up in sugar, vitamin A, and glycemic response rather than fiber. Our sweet potato vs. regular potato comparison covers the rest.
Is the fiber in sweet potato soluble or insoluble?
Both. Sweet potato flesh contains soluble fiber including pectin, while the skin contributes mostly insoluble fiber such as cellulose. Eating the whole potato gives you a mix of the two.
Does dried sweet potato still have fiber?
Yes. Drying removes water, not fiber, so dried sweet potato concentrates the fiber into a smaller, lighter portion. That is why a modest handful of dried sweet potato can deliver as much fiber as a chunk of the fresh vegetable.
A Simpler Way to Get Sweet Potato Fiber
Roasting a sweet potato is great when you have an oven and forty minutes. When you do not, that fiber usually gets skipped. Yammy sweet potato sticks solve the timing problem by starting with real sweet potato and drying it into a chewy stick that eats like a fruit leather, with 4 grams of fiber and 3 grams of protein per serving. They are naturally vegan and gluten-free, and they are never deep-fried. The Original, Salt & Pepper, and Sriracha flavors have no added sugar.
Browse the full lineup of sweet potato sticks, or dig deeper into nutrition, varieties, and prep in our complete sweet potato guide.