Is Bananas Keto? Carbs, Net Carbs & Verdict
Is bananas keto? No — one medium banana has ~24g net carbs, enough to use a full day's keto budget. Here's the carb breakdown and low-carb swaps.
Head of Nutrition · June 20, 2026 · 5 min read
No — bananas are not keto-friendly. One medium banana has about 24g of net carbs (27g total carbs minus ~3g fiber), and per 100g a banana runs roughly 20g net carbs. Because a typical keto plan caps you at 20–50g of net carbs per day, a single banana can swallow your entire allowance in one snack. Bananas are one of the most sugar-dense common fruits, so they don't fit strict keto — and even half a banana is a stretch. Reach for berries instead.
Bananas have a strong "healthy" reputation — they're potassium-rich, portable, and a classic pre-workout snack. But on keto, the only numbers that matter are carbs and sugar, and bananas are loaded with both. Here's the full breakdown, portion guidance, and the best low-carb fruits to eat instead.
Is bananas keto?
No. A banana is one of the worst fruits for a ketogenic diet. To stay in ketosis, most people keep net carbs under 20–50g per day, with strict keto closer to 20g. A single medium banana lands at roughly 24g of net carbs — meaning one banana alone can blow past a strict daily limit before you've eaten anything else.
The riper the banana, the worse it gets for keto. As bananas ripen, their resistant starch converts to simple sugars, so a spotty, sweet banana spikes blood sugar faster than a firmer green one. Either way, the total carb load is high enough to interrupt ketosis for most people.
How many carbs are in bananas?
Bananas are mostly carbohydrate by composition, with very little fat or protein and only a modest amount of fiber. That means most of their carbs count toward your net total. Here's how common servings stack up:
| Serving | Total carbs | Fiber | Net carbs |
|---|---|---|---|
| Small banana (~101g) | ~23g | ~2.6g | ~20.4g |
| Medium banana (~118g) | ~27g | ~3.1g | ~23.9g |
| Large banana (~136g) | ~31g | ~3.5g | ~27.5g |
| Half medium banana | ~13.5g | ~1.5g | ~12g |
| 100g (about 2/3 banana) | ~22.8g | ~2.6g | ~20.2g |
A medium banana also carries about 14g of sugar and roughly 105 calories. To compute net carbs, you subtract fiber from total carbs — and because a banana has only ~3g of fiber against ~27g of total carbs, there's very little to subtract. (New to the math? See our guide to what is net carbs.)
How much bananas can you eat on keto?
Honestly, very little. On strict keto (20g net carbs/day), even a quarter of a banana (~6g net) is a meaningful chunk of your budget, and a half (~12g net) leaves almost no room for vegetables, nuts, or dairy the rest of the day.
On a more lenient low-carb plan (50g net carbs/day), you have a bit more flexibility — a half banana could fit if you keep the rest of your day tight. But you'll almost always get more nutrition and satisfaction per carb from berries. If you're craving banana specifically for potassium, leafy greens, avocado, and salmon deliver it without the sugar.
Bottom line: a whole banana doesn't belong on keto, and even a half is a judgment call best reserved for higher-carb days.
Best low-carb alternatives to bananas
You don't have to give up sweet, fresh fruit on keto — you just have to swap bananas for lower-sugar options. Here's how the best alternatives compare per 1/2-cup serving:
| Fruit (1/2 cup) | Net carbs | Keto-friendly? |
|---|---|---|
| Raspberries | ~3g | Yes |
| Blackberries | ~3g | Yes |
| Strawberries | ~4g | Yes |
| Blueberries | ~9g | In moderation |
| Avocado (1/2 fruit) | ~2g | Yes |
| Banana (medium) | ~24g | No |
Berries are the clear winners — raspberries, blackberries, and strawberries are high in fiber and water, which keeps net carbs low while still tasting sweet. Avocado is technically a fruit and a keto staple at ~2g net carbs per half. For more options, see our roundup of keto-friendly fruits.
If you specifically miss banana flavor, look for banana extract (zero-carb flavoring) to add to keto smoothies, yogurt, or fat bombs — you get the taste without the sugar load.
Why bananas aren't keto
Two things knock bananas off the keto list:
- High carb density. At ~24g net carbs each, a banana leaves essentially no room for other foods in a strict keto day. Ketosis depends on keeping total carbs very low, and one banana makes that nearly impossible.
- Fast-digesting sugar. Ripe bananas are rich in glucose and fructose with a moderate-to-high glycemic load, so they raise blood sugar and insulin quickly. Insulin signals your body to store fat and stop burning it — the opposite of what ketosis is built to do.
"Plantains," "baby bananas," and banana chips don't help either. Banana chips are often fried and sweetened, packing 30g+ of carbs per ounce, and plantains are even starchier than bananas.
Track bananas before they wreck your budget
Bananas are an obvious high-carb fruit, but their carbs also hide inside smoothies, "healthy" muffins, banana bread, protein shakes, and granola — places where one banana's 24g can quietly blow your day. CarbMeNot is an AI-powered iOS app that lets you snap a photo or scan a barcode and instantly see real net carbs, so you'll know whether that banana (or banana smoothie) fits before you eat it. Log your bananas in CarbMeNot and watch how fast they eat your keto budget — then swap in berries and stay in ketosis.
Key takeaways
- Bananas are not keto-friendly. One medium banana has ~24g net carbs — enough to use a full day's strict keto budget.
- Per 100g, a banana has about 20g net carbs; per medium fruit, ~27g total carbs and ~3g fiber.
- Riper bananas are worse, as resistant starch converts to fast-digesting sugar.
- Even half a banana (~12g net) is hard to fit on strict keto — reserve it for lenient, higher-carb days.
- Swap in berries (3–4g net per 1/2 cup) or avocado (~2g) for sweet fruit without the sugar load.
- Let CarbMeNot catch hidden banana carbs in smoothies and baked goods so you always know your true net carbs.
Frequently asked questions
- Is bananas keto?
- No, bananas are not keto-friendly. One medium banana has about 24g of net carbs (27g total carbs minus ~3g fiber), which can use up an entire day's keto carb budget of 20–50g on its own. Bananas are one of the highest-sugar fruits, so even half a banana is hard to fit into strict keto.
- How many carbs are in bananas?
- One medium banana (about 118g) has roughly 27g of total carbs, 3.1g of fiber, and about 24g of net carbs, along with ~14g of sugar and ~105 calories. Per 100g, a banana has about 22.8g total carbs, 2.6g fiber, and roughly 20.2g net carbs.
- Can you eat half a banana on keto?
- Half a medium banana has about 12g of net carbs, which is still more than half of a strict 20g daily keto limit. It can occasionally fit a lenient low-carb day if you plan the rest of your meals around it, but on standard keto it's usually wiser to choose berries instead.
- What fruit can I eat instead of a banana on keto?
- Berries are the best swap: 1/2 cup of raspberries (~3g net carbs), blackberries (~3g), or strawberries (~4g) deliver natural sweetness at a fraction of a banana's carbs. Avocado (~2g net per half) is also technically a fruit and a keto staple.
Sources
Track it all in seconds
Snap a photo and CarbMeNot's AI logs your carbs, protein, and fat automatically.
