Yes, but only a modest one. A whole medium cucumber with skin on, about 300 grams, delivers roughly 1.5 grams of dietary fiber, while a cup of sliced skin-on cucumber holds about 0.6 to 0.8 grams, based on United States Department of Agriculture (USDA) FoodData Central values. Because cucumber is about 95% water by weight, the USDA classifies it (Cucumis sativus) as a low-fiber food rather than a fiber-rich one.
For anyone tracking fiber intake or building a high-fiber diet, this guide breaks down what cucumber actually contributes gram-for-gram and why its water content keeps it from being a fiber powerhouse.
Cucumber’s Fiber Content by Serving Size
Raw, unpeeled cucumber delivers roughly 0.5 grams of fiber per 100 grams in the USDA database, which sets the baseline for every portion you’ll measure. Because cucumber is about 95% water, even a generous serving barely nudges a daily fiber goal.
Serving size still shifts the totals more than most people expect. A whole medium cucumber weighs close to 300 grams with skin on, pushing fiber up to around 1.5 grams. A single cup of sliced cucumber, roughly 119 grams, lands closer to 0.6 grams. You would need to eat two or three whole cucumbers in one sitting to make the fiber numbers feel substantial.
| Serving | Weight | Fiber (approx.) |
|---|---|---|
| Raw cucumber, skin-on | 100 g | 0.5 g |
| Whole medium cucumber, skin-on | 300 g | 1.5 g |
| Cup of sliced cucumber, skin-on | 119 g | 0.6–0.8 g |
| Peeled cucumber, per 100 g | 100 g | 0.3–0.4 g |
Peeled portions lose a meaningful share of an already small total, falling to around 0.3 to 0.4 grams per 100 grams. Most nutrition labels and tracking apps round cucumber’s fiber contribution to half a gram per serving, and that rounding actually flatters the real-world impact.
Why Cucumbers Rank Low on the Fiber Scale
The short answer is water. Cucumber tops the hydration chart among common vegetables, which sounds healthy until you realize water displaces almost everything else, including fiber.
Water Leaves Little Room for Fiber
At roughly 95% water by weight, cucumber has one of the lowest dry-matter percentages of any raw vegetable you eat. Fiber lives in structural parts of the plant, the cell walls and the skin, and those make up only a sliver of total mass. The result is a vegetable that feels substantial in your hand but contributes only trace fiber per bite.
Low Calories Track With Low Fiber Density
Cucumber provides about 15 to 16 calories per 100 grams, which is why it shows up on weight-loss plates and low-calorie snack swaps. That low energy density tracks directly with low fiber density. Vegetables that concentrate fiber, like Brussels sprouts, artichokes, and leafy greens, tend to be drier, denser, and higher in calories per bite.
Glycemic Impact Stays Muted
Cucumber’s glycemic index sits near 15, one of the lowest values in the produce aisle. Blood sugar barely moves after a serving, even with low fiber, because the total carbohydrate count is tiny. That makes cucumber gentle on glucose, but it also means you won’t get the blood-sugar buffering effect that higher-fiber foods provide.
That nutritional modesty also depends on whether you eat the skin, which carries most of the fiber.
What Changes When You Leave the Skin On
Leaving the skin on is the single most effective move for squeezing more fiber from a cucumber. The peel holds the majority of what the vegetable actually contains.
Where the Fiber Lives
Most of cucumber’s fiber sits in the dark green outer layer. The inner flesh is mostly water with a soft cellulose structure. Strip the peel with a vegetable peeler and you remove the densest fiber zone first. For a 100 gram serving, peeling can cut fiber by 30% to 40%, pushing totals from 0.5 grams down toward 0.3 grams.
Bonus Compounds in the Peel
Skin-on cucumber also carries trace antioxidants and polyphenols, including flavonoids like quercetin and apigenin, plus small amounts of vitamin K and beta-carotene concentrated near the surface. The amounts stay modest, but they reinforce a useful pattern: the closer you eat to the whole vegetable, the more nutritional return you get per bite.
Practical tip: Skip the peeler for salads or dipping. A quick scrub with cool water cleans the skin and keeps the fiber intact.
Soluble Versus Insoluble Fiber in Cucumber
Both soluble and insoluble fiber show up in a cucumber, yet the total stays modest even in a generously sliced serving. The split explains why cucumber feels hydrating rather than filling.
Insoluble Fiber Does Most of the Work
Roughly two-thirds of the fiber inside a cucumber is insoluble, the type that swells with water and helps stool move through the gut. Pectin shows up in small amounts too, acting as a gentle soluble fiber. Because the total fiber count is so low, the bulk-forming effect stays subtle. You won’t rely on cucumber alone for digestive regularity, though it adds a small nudge in the right direction.
Soluble Fiber Plays a Minor Role
Soluble fiber in cucumber runs well under half a gram per cup. That fraction can support gentle blood-sugar control and feed beneficial gut bacteria, but the dose is too small to drive meaningful changes on its own. Pairing cucumber with higher-fiber foods amplifies both effects.
These modest amounts still matter, especially once you see how cucumber stacks up against vegetables with denser fiber profiles.
How Cucumber Compares to Common Vegetables
Side by side with other popular vegetables, cucumber’s fiber totals look thin, especially after you factor in calories per serving. The gap becomes obvious fast.
| Vegetable | Fiber per 100 g | Calories per 100 g |
|---|---|---|
| Cucumber (raw, skin-on) | 0.5 g | 15 kcal |
| Broccoli (raw) | 2.6 g | 34 kcal |
| Carrots (raw) | 2.8 g | 41 kcal |
| Spinach (cooked) | 2.2 g | 23 kcal |
| Kale (raw) | 3.6 g | 49 kcal |
Broccoli delivers roughly five times cucumber’s fiber per 100 grams, and kale pushes that gap past seven times. Spinach, even cooked, still offers more than four times cucumber’s fiber density. Carrots fall somewhere in the middle, well ahead of cucumber but below the leafy greens.
Fiber Per Calorie Tells the Same Story
Looking at fiber per 100 calories sharpens the picture. Cucumber lands near 3.3 grams per 100 calories, respectable for a hydration food but far below broccoli’s roughly 7.6 grams or kale’s about 7.3 grams per 100 calories. If your goal is maximum fiber per bite, denser vegetables win every time.
Since cucumber can’t anchor your fiber intake alone, the real question becomes how to slot it into a day built around stronger sources.
Making Cucumber Work in a Fiber-Focused Diet
Cucumber earns its place on the plate for hydration, crunch, and micronutrients, not as a primary fiber source. The smartest approach treats it as a complement to denser fiber foods rather than a replacement for them.
Pair Cucumber With Fiber-Dense Foods
Combining cucumber with legumes, seeds, or whole grains is where the math starts to work. A Mediterranean bowl with chickpeas, about 6 grams of fiber per half cup, a handful of pumpkin seeds, roughly 1.7 grams per ounce, and a generous scoop of cucumber adds up quickly. The cucumber brings water and crunch while the other ingredients carry the fiber load.
- Add chickpeas or lentils: Toss a half cup into a cucumber salad to add 6–8 grams of fiber.
- Sprinkle chia or flax seeds: One tablespoon contributes 2–3 grams of fiber without changing the flavor.
- Layer over whole grains: Use cucumber as a topping for farro, bulgur, or brown rice bowls.
- Pair with nuts: Almonds or walnuts add fiber plus healthy fats for a satisfying snack.
Build Habits Around the Skin-On Choice
Choosing skin-on cucumber consistently is the easiest fiber bump you can make. For crudité platters, leave spears unpeeled. For salads, slice thin-skinned English cucumbers whole. Even for tzatziki, grate the cucumber with skin intact and just drain off the excess liquid. The fiber total climbs quietly in the background.
Use Pickled Cucumbers Mindfully
Pickling preserves fiber because cucumbers are typically brined with skin on. The fiber content stays close to fresh values, but sodium climbs sharply. A single dill pickle spear can carry 250 to 400 milligrams of sodium. If you track sodium for blood pressure or heart health, treat pickles as a condiment rather than a daily fiber vehicle.
Match Cucumber Against Realistic Daily Targets
The Dietary Guidelines for Americans recommend about 14 grams of fiber per 1,000 calories, which works out to roughly 25 grams per day for adult women and 38 grams per day for adult men, figures also cited by the American Heart Association. Eating a whole medium cucumber delivers about 1.5 grams, roughly 4% to 6% of those targets. Useful, but not a shortcut.
Bottom Line
Cucumber is a hydration food with a small fiber bonus, not a fiber workhorse. Eat the skin on, pair it with legumes or seeds, and let denser vegetables like broccoli, kale, and carrots carry the heavy fiber lifting your body actually needs each day.
FAQ
Is cucumber a fiber food?
A whole peeled cucumber delivers about one gram of fiber, so it qualifies as a fiber source, just not a concentrated one.5 grams per 100 grams with skin on. The USDA classifies it as a low-fiber food because its 95% water content leaves very little dry matter for fiber to concentrate in.
How much fiber does a cucumber have?
A whole medium cucumber with skin, about 300 grams, provides around 1.5 grams of fiber. One cup of sliced cucumber with skin holds about 0.6 to 0.8 grams, while the same serving peeled drops to roughly 0.4 grams.
Does eating the cucumber skin increase fiber?
Yes, meaningfully. The peel holds most of cucumber’s fiber, both soluble and insoluble forms. Leaving the skin on can boost fiber by 30% to 40% compared to peeled slices, plus add small amounts of antioxidants and polyphenols.
Is cucumber good for digestion?
Water makes up roughly 95 percent of a cucumber, and that fluid content along with its modest insoluble fiber helps keep digestion steady. It is not a strong digestive aid on its own, but it pairs well with higher fiber foods in a gut-healthy diet.
Is cucumber considered a high fiber vegetable?
No. Cucumber ranks near the bottom of common vegetables for fiber density. Broccoli, kale, carrots, spinach, artichokes, and Brussels sprouts all deliver several times more fiber per 100 grams, making cucumber a hydration food rather than a high fiber choice.
What are the main nutritional benefits of cucumber?
Cucumber delivers hydration through its 95% water content, a small fiber contribution, vitamin K, modest vitamin C, trace antioxidants like quercetin, and very few calories. Its strength lies in volume, crunch, and low energy density rather than concentrated nutrition.
