How Many Calories in Kefir? Nutrition Facts & Macros
One cup of kefir (243g) has 104 calories
Protein 9.2g · Carbs 11.6g · Fat 2.5g
Kefir is a fermented milk drink that originated in the Caucasus Mountains. It's made by adding kefir grains — a symbiotic culture of bacteria and yeast — to milk, producing a tangy, slightly effervescent beverage packed with probiotics. Unlike yogurt which typically contains 2-3 bacterial strains, kefir can harbor up to 61 different strains of bacteria and yeast, making it one of the most probiotic-rich foods available. Lowfat plain kefir is about 87.5% water.
180 kJ · per 100g · Water: 87.5 g
Calorie Calculator: Kefir (Lowfat, Plain)
243 g Kefir (Lowfat, Plain) contains 104 kcal
Calories by Portion Size
| Portion | Calories | Protein | Carbs | Fat |
|---|---|---|---|---|
| 1 cup (243g) | 104 kcal | 9.2g | 11.6g | 2.5g |
| 1 bottle (971g) | 418 kcal | 36.8g | 46.3g | 9.9g |
| 100 grams | 43 kcal | 3.8g | 4.8g | 1g |
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Kefir (Lowfat, Plain) — Nutrition Facts
| Kefir (Lowfat, Plain) | per 100g |
|---|---|
| Calories | 43 kcal |
| Protein | 3.79 g |
| Fat | 1.02 g |
| Carbs | 4.77 g |
| Fiber | 0 g |
| Sugar | 4.61 g |
| Sodium | 40 mg |
| Potassium | 164 mg |
| Phosphorus | 105 mg |
| Water | 87.5 g |
Source: USDA FoodData Central (FDC ID: 170904) · Data verified April 2026
Variations
Whole milk kefir
About 63 calories per 100g with 3.3g protein and 3.5g fat. Creamier and richer flavor than lowfat. The higher fat content improves satiety and absorption of fat-soluble vitamins (A, D, E, K). Better choice for keto diets.
Flavored kefir
About 67 calories per 100g due to added fruit and sugar. Carbs jump to ~10g per 100g (vs 4.77g plain). Probiotics remain similar. For fewer carbs and less sugar, choose plain kefir and blend it with fresh berries yourself.
Goat milk kefir
About 55 calories per 100g with a tangier, more complex flavor. Goat milk has smaller fat globules and different casein structure (A2), which may be easier to digest for some people. Similar probiotic content to cow's milk kefir. Often preferred by those with cow's milk sensitivity (not allergy).
Dietary Perspectives
For Weight Loss
At just 43 kcal per 100 g, kefir is one of the lowest-calorie fermented dairy options. It provides 3.79 g of protein with only 1.02 g of fat and 4.77 g of carbohydrates per 100 g. A full cup (243 g, ~104 kcal) is very filling as a drink. The probiotics (up to 61 strains) may support weight management by improving gut microbiome diversity. Its high water content (87.5%) adds satisfying volume without calories. Use it as a smoothie base, salad dressing ingredient, or light snack.
For Athletic Performance
Kefir provides 3.79 g of protein per 100 g — a blend of casein (slow) and whey (fast) proteins. A cup (243g) delivers 9.2g of protein and 130mg of calcium (32% DV per cup), important for bone density. B vitamins (especially B12 at 0.29 mcg/100g and riboflavin at 0.135mg/100g) support energy metabolism. Kefir's drinkable format makes it a convenient post-workout option — mix with banana and oats for a recovery shake. Probiotics may also improve nutrient absorption.
For Keto
Kefir has 4.77 g of net carbs per 100 g (4.77 g total carbohydrates, 0 g fiber). One cup (243 g) contains 11.6 g of net carbs — which takes up a significant portion of a strict 20 g keto daily budget. For strict keto, limit to half a cup (~6 g net carbs) or choose whole milk kefir for better fat-to-carb ratio. For relaxed keto or low-carb (50 g daily), a full cup fits easily. The fermentation reduces lactose by ~30%, and probiotics support digestive adaptation during the keto transition.
Frequently Asked Questions
How many calories are in kefir?
One cup (243g) of lowfat plain kefir contains approximately 104 calories. Per 100g, it has only 43 calories — significantly less than Greek yogurt (97 kcal) or whole milk kefir (~63 kcal). The low calorie count comes from its reduced fat content (1.02g per 100g).
How much protein is in kefir?
Kefir contains 3.79g of protein per 100g, or about 9.2g per cup (243g). The protein is a mix of casein and whey. While lower than Greek yogurt (9g per 100g), kefir's liquid form makes it easy to consume as a drink alongside meals, boosting your daily protein intake conveniently.
What are the health benefits of kefir?
Kefir is one of the richest dietary sources of probiotics, containing up to 61 strains of bacteria and yeast. These probiotics support gut health, digestion, and immune function. Kefir also provides 130mg of calcium per 100g (10% DV), 171 mcg of vitamin A (19% DV), and B vitamins. Fermentation breaks down about 30% of the lactose, making it better tolerated by people with lactose sensitivity.
Kefir vs yogurt — what's the difference?
Kefir: 43 kcal, 3.79g protein, 4.77g carbs, 1.02g fat per 100g. Yogurt: 61 kcal, 3.47g protein, 4.66g carbs, 3.25g fat. The key difference is probiotics — kefir contains up to 61 strains vs yogurt's 2-3. Kefir is drinkable and thinner, yogurt is spoonable. Kefir has more vitamin A and calcium. Fermentation also makes kefir lower in lactose.
How many carbs are in kefir? Is kefir good for keto?
Lowfat kefir has 4.77g of carbs per 100g, mostly from lactose. One cup (243g) contains 11.6g of net carbs — which may be too much for strict keto (under 20g daily) but fits well into a relaxed keto or low-carb diet. The fermentation process reduces the lactose content by about 30% compared to unfermented milk.
Is kefir good for weight loss?
Kefir is excellent for weight loss. At only 43 kcal per 100g, it's one of the lowest-calorie fermented dairy options. A full cup (243g, 104 kcal) is very filling as a drink. The probiotics may also support weight management by improving gut microbiome diversity. Its high water content (87.5%) adds volume without calories. Use it as a meal base, smoothie ingredient, or satisfying snack.
Compare with Similar Foods
| Portion | kcal | Protein | Carbs | Fat |
|---|---|---|---|---|
| Kefir (Lowfat, Plain) | 43 | 3.79g | 4.77g | 1.02g |
| Greek Yogurt (Whole Milk) | 97 | 9g | 3.98g | 5g |
| Yogurt | 61 | 3.47g | 4.66g | 3.25g |
| Milk (Whole) | 61 | 3.15g | 4.8g | 3.25g |
| Cottage Cheese | 98 | 11.12g | 3.38g | 4.3g |
per 100g
Kefir has just 43 kcal per 100g with 3.79g of protein — fewer calories than yogurt (61 kcal) or Greek yogurt (97 kcal). Its real advantage is probiotics: up to 61 strains vs yogurt's 2-3, making it one of the most gut-friendly dairy products.
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