Kohlrabi Nutrition Facts and Health Benefits

Kohlrabi doesn’t have a PR team. Nobody’s putting it on superfood lists or blending it into celebrity smoothies. But when you actually look at what’s inside this unassuming bulb, the numbers are kind of ridiculous.

More vitamin C than an orange. Fewer calories than practically anything else in the produce aisle. A solid hit of fiber, potassium, and B vitamins. All from a vegetable most people can’t even identify.

Let’s break it down.

Kohlrabi Nutrition Facts (Per Cup, Raw)

One cup of raw kohlrabi (about 135 grams, chopped) gives you:

Nutrient	Amount	% Daily Value
Calories	36	—
Protein	2.3 g	5%
Total Fat	0.1 g	<1%
Carbohydrates	8.4 g	3%
Fiber	4.9 g	17%
Sugar	3.5 g	—
Vitamin C	83.7 mg	93%
Vitamin B6	0.2 mg	12%
Potassium	473 mg	10%
Manganese	0.2 mg	9%
Phosphorus	62 mg	5%
Copper	0.2 mg	9%
Folate	22 mcg	5%

At 36 calories per cup, kohlrabi is absurdly low in energy for the amount of nutrition it delivers. For context, that’s fewer calories than a single tablespoon of olive oil.

Vitamin C: The Headline Act

Here’s the fact that should be on a billboard somewhere: one cup of raw kohlrabi contains about 93% of your daily vitamin C needs. That’s more than a medium orange (about 70 mg) and roughly on par with a cup of raw broccoli.

Vitamin C is an antioxidant, meaning it helps protect cells from damage caused by free radicals. It also supports collagen production (important for skin, joints, and wound healing), helps your body absorb iron from plant-based foods, and plays a role in immune function.

The catch — and this matters — is that vitamin C breaks down with heat. If you boil kohlrabi until it’s soft, you’ll lose a significant chunk of that vitamin C. Eating kohlrabi raw, lightly steamed, or quickly stir-fried preserves more of it.

Fiber: Quietly Impressive

Nearly 5 grams of fiber per cup puts kohlrabi ahead of many common vegetables. For reference, a cup of raw broccoli has about 2.4 grams. A medium apple has about 4.4 grams. Kohlrabi beats both.

That fiber is a mix of soluble and insoluble types. Soluble fiber slows digestion and can help moderate blood sugar spikes after meals. Insoluble fiber adds bulk and keeps things moving through your digestive tract. Most people don’t eat enough of either kind — the average American gets about 15 grams a day against a recommended 25 to 30.

One cup of kohlrabi gets you about a fifth of the way there. Not bad for a side dish.

Potassium: The Underrated Mineral

At 473 mg per cup, kohlrabi is a genuinely good source of potassium. That’s more than a medium banana (about 422 mg), though admittedly the banana gets more press.

Potassium helps regulate fluid balance, muscle contractions, and nerve signals. Diets higher in potassium are consistently associated with lower blood pressure in research, which is why the American Heart Association encourages eating potassium-rich foods. Kohlrabi is an easy, low-calorie way to get there.

Antioxidants Beyond Vitamin C

As a brassica (the family that includes broccoli, kale, and cabbage), kohlrabi contains glucosinolates — sulfur-containing compounds that break down into biologically active molecules during digestion. Research on glucosinolates has focused heavily on their potential role in reducing oxidative stress and supporting the body’s natural detoxification processes.

Kohlrabi also contains anthocyanins, particularly in the purple-skinned varieties. These are the same pigment compounds found in blueberries and red cabbage. While the flesh inside is white regardless of skin color, purple kohlrabi delivers a small extra dose of these antioxidants from the peel if you eat it (the skin of young, tender kohlrabi is totally edible).

Carotenoids and phenolic compounds round out the antioxidant profile. None of this makes kohlrabi a magic bullet, but it’s a legitimately nutrient-dense food for its calorie count.

How Kohlrabi Stacks Up Against Other Brassicas

Kohlrabi often gets compared to its more famous relatives. Here’s how it holds up per cup (raw):

Nutrient	Kohlrabi	Broccoli	Cauliflower	Cabbage
Calories	36	31	27	22
Fiber	4.9 g	2.4 g	2.1 g	2.2 g
Vitamin C	84 mg	81 mg	52 mg	33 mg
Potassium	473 mg	288 mg	303 mg	151 mg
Protein	2.3 g	2.6 g	2.1 g	1.1 g

Kohlrabi wins on fiber and potassium by a comfortable margin, ties with broccoli on vitamin C, and holds its own on protein. Its calorie count is slightly higher than cabbage or cauliflower but still negligible in any practical sense.

The takeaway: kohlrabi isn’t just “as good as” the popular brassicas. In several categories, it’s genuinely better. For a closer look at how another brassica stacks up, see our comparison with Brussels sprouts nutrition — another low-carb powerhouse in the family.

Kohlrabi and Weight Loss

If you’re watching calories, kohlrabi is almost comically friendly. At 36 calories per cup with nearly 5 grams of fiber, it’s the kind of food that fills you up without budging the calorie count.

The fiber-to-calorie ratio is the key. High-fiber foods take longer to chew, slow stomach emptying, and promote satiety — that feeling of actually being satisfied after eating. Swap kohlrabi sticks for chips as a snack vehicle and you’re looking at a fraction of the calories with more staying power. Try kohlrabi fries or mashed kohlrabi as a potato substitute for satisfying low-carb alternatives.

It also has a high water content (about 91%), which adds volume to meals. Volume-based eating strategies — sometimes called volumetrics — are one of the more evidence-supported approaches to managing weight without feeling hungry all the time.

Kohlrabi and Immune Health

The vitamin C connection is the obvious one here. Adequate vitamin C intake supports multiple aspects of immune function, including the production and function of white blood cells and the maintenance of skin barriers.

But the glucosinolates matter too. Some research suggests that the breakdown products of glucosinolates — particularly sulforaphane, found across the brassica family — may support the body’s inflammatory response, though most of this research is still in early stages (cell and animal studies, primarily).

The practical point: eating kohlrabi regularly as part of a varied diet gives your immune system several different types of nutritional support, not just one.

Kohlrabi and Digestive Health

The fiber content alone makes kohlrabi a friend to your gut. But there’s more to it. The prebiotic fiber in kohlrabi feeds beneficial gut bacteria, supporting a healthy microbiome. A well-fed microbiome is linked to better digestion, improved nutrient absorption, and even mood regulation (the gut-brain connection is real, if still being mapped out).

The high water content also supports digestion by keeping things hydrated as they move through your system. If you’ve ever added more fiber to your diet without drinking enough water, you know that fiber alone isn’t the whole picture.

Raw vs. Cooked: Does It Matter?

Nutritionally, raw kohlrabi preserves the most vitamin C and keeps those glucosinolates intact. Cooking — especially boiling — leaches water-soluble vitamins into the cooking liquid and can degrade heat-sensitive compounds.

That said, cooked kohlrabi is still good for you. Steaming and roasting retain more nutrients than boiling. And cooking can make some nutrients more bioavailable, meaning your body absorbs them more efficiently.

The best approach? Eat it both ways. Raw in slaws and snack plates to maximize vitamin C. Roasted or steamed as a side dish for variety and warmth. Your body benefits either way.

The Bottom Line

Kohlrabi is one of the most nutrient-dense vegetables per calorie that you can eat. It outperforms oranges on vitamin C, bananas on potassium, and most common vegetables on fiber. It’s low in calories, high in water, and packed with the kind of compounds that nutritional research keeps flagging as important.

It’s not a superfood — because that term doesn’t mean anything. It’s just a really, really good vegetable that deserves a regular spot in your kitchen.