Cucumbers are low in carbohydrates, with about 4 grams of total carbs per cup, making them a popular choice for low-carb and keto diets.
Cucumbers are mostly water — roughly 96% by weight — which is why they’re so refreshing in summer salads and water jugs. But if you’re counting carbohydrates, that high water content might make you wonder whether the carbs are hiding somewhere.
The short answer is yes: cucumbers are genuinely low in carbs. One cup of chopped cucumber (roughly 104 grams) contains about 4 grams of total carbohydrates, and with the skin on, it’s closer to 2.95 grams per 100 grams — well within the range for low-carb and keto diets. This article breaks down the exact carb counts, how peeling affects them, and why cucumbers earn a regular spot on low-carb meal plans.
How Many Carbs Are In A Cucumber
Carb Count By Preparation
Carb counts for cucumber depend on the serving size and whether the skin is left on. A standard one-cup serving of chopped cucumber (about 104 grams) provides roughly 4 grams of total carbohydrates, according to Healthline’s vegetable carb database. That same serving delivers only 16 calories and negligible protein and fat.
When the skin is intact, the numbers shift slightly. Medical News Today reports that cucumbers with the skin offer about 2.95 grams of carbohydrates per 100 grams. This places cucumber among the lowest-carb vegetables available, especially compared to starchy options like potatoes or carrots.
If you peel the cucumber, the carb content drops a bit further. Medical News Today suggests peeling as one way to reduce carbs for strict keto dieters. The difference is small — roughly half a gram per cup — but worth noting if you’re counting every gram.
A half-cup serving (about 52 grams) of sliced cucumber contains roughly 2 grams of total carbs. For most people, that means you can eat a generous bowl of cucumber salad without worrying about your daily limit.
Why Cucumbers Fit So Well Into Low-Carb Meal Plans
Cucumbers aren’t just low in carbs; they bring texture, volume, and versatility that make low-carb eating feel less restrictive. Here’s why they’re a go-to for many people following low-carb or keto diets:
- High water content keeps you full — Cucumbers are about 96% water, which means they add bulk to meals without adding many calories or carbs. That makes them a smart base for salads, snack plates, and wraps.
- Net carbs are minimal — A cup of cucumber has about 3 grams of net carbs (total carbs minus fiber), according to Weight Watchers’ low-carb vegetable list. This number fits easily into most daily carb limits, especially on a standard keto budget of 20 to 50 grams per day.
- Above-ground advantage — Cucumbers are an above-ground vegetable, which generally means they’re lower in net carbs than below-ground options like carrots or beets. Diet Doctor notes that above-ground vegetables stay under 5 grams of net carbs per 100 grams.
- Pairs well with other low-carb foods — Cucumber teams up naturally with other low-carb staples like green olives, cauliflower, and zucchini, as Atkins’ low-carb vegetable guide points out. You can build an entire meal around them without exceeding carb goals.
- Versatile and affordable — Cucumbers work raw in salads, pickled as a condiment, spiralized into noodles, or sliced for dipping. Their mild flavor and crunch adapt to almost any low-carb recipe, from keto tacos to crunchy veggie platters.
For most low-carb and keto eaters, cucumber is a free vegetable — one you don’t need to measure strictly. As long as you account for the total across the day, a whole cucumber is unlikely to push you over your limit.
Cucumber Carb Counts At A Glance
To make the numbers easy to compare, here’s a breakdown of cucumber carb content by serving size and preparation. One cup of chopped cucumber contains about 4 grams of total carbs — a figure from Healthline’s cucumber carb content per cup. The table below pulls together data from several sources to give you a quick reference.
| Serving Size | Total Carbs | Net Carbs (approx.) |
|---|---|---|
| 1 cup, chopped (104g) with skin | ~4 g | ~3 g |
| 100 g, with skin | ~2.95 g | ~2.5 g |
| ½ cup, sliced (52g) | ~2 g | ~1.6 g |
| 1 large cucumber (280g), unpeeled | ~10 g | ~8.5 g |
| 1 medium cucumber (200g), peeled | ~5.5 g | ~4.5 g |
These numbers confirm that cucumber stays comfortably low in carbs across most serving sizes. The biggest factor is simply how much you eat — a whole large cucumber adds noticeable carbs, but a cup or two for a salad is negligible.
Ways To Keep Cucumber Carbs Even Lower
If you’re on a strict keto or low-carb plan, a few simple tricks can reduce the carbs in your cucumber even further without sacrificing crunch.
- Peel the skin — The skin of a cucumber contains a small amount of additional fiber and carbohydrates. Medical News Today recommends peeling if you want the absolute lowest carb count.
- Slice instead of chunk — Thin slices spread out over a larger surface area, making you feel like you’re eating more cucumber with fewer total carbs per serving. A mandoline slicer works well for this.
- Pair with protein or fat — Eating cucumber with a fat source like cream cheese or guacamole doesn’t change the carb count, but it can slow digestion and help stabilize blood sugar, which some people find beneficial for appetite control.
- Watch serving size for large cucumbers — A large cucumber (about 280g) can have over 10 grams of total carbs. If you eat a whole large cucumber, account for it in your daily total rather than treating it as free food.
These strategies are optional — for most people, a standard cucumber serving fits easily within low-carb limits without any modification. But if you’re carb‑sensitive, peeling and portion control make a small difference.
How Cucumber Compares To Other Low-Carb Vegetables
Cucumber isn’t the only low-carb vegetable, but it’s among the lowest. Above‑ground vegetables tend to stay under 5 grams of net carbs per 100 grams, while below‑ground veggies like carrots and potatoes run higher. A half‑cup of cucumber slices provides only 1.6 grams of net carbs, according to Lowcarbyum’s half cup cucumber net carbs — effectively negligible for most meal plans.
Quick Comparison Table
For a direct comparison, here’s how cucumber stacks up against other popular low‑carb vegetables per standard cup serving.
| Vegetable (1 cup chopped) | Total Carbs | Net Carbs |
|---|---|---|
| Cucumber | ~4 g | ~3 g |
| Cauliflower | ~5 g | ~3 g |
| Zucchini | ~4 g | ~3 g |
| Green Olives (1 oz) | ~1 g | ~0.5 g |
Cucumber holds its own against other low‑carb staples. Its net carb count is similar to cauliflower and zucchini, making it an interchangeable ingredient in many keto recipes. If you’re looking to diversify your vegetable list, cucumber is a safe and satisfying option.
The Bottom Line
Cucumbers are a low‑carb vegetable that fits easily into keto, Atkins, Weight Watchers, or general low‑carb eating. With about 4 grams of total carbs per cup and a water content of 96%, they offer hydration, crunch, and volume without spiking your carb count. Most people can eat a full cucumber without worrying about their daily limits, though portion size matters for strict keto dieters.
If you’re managing a condition that requires precise carb counting, such as diabetes or gestational diabetes, a registered dietitian can help you fit cucumber into your specific meal plan based on your blood sugar targets and medication schedule.
References & Sources
- Healthline. “21 Best Low Carb Vegetables” One cup (104 g) of chopped cucumber contains 4 grams of total carbohydrates.
- Lowcarbyum. “Are Cucumbers Keto Friendly” A ½ cup of cucumber slices contains just 1.6 g of net carbs.