Calories in Kefir: Nutrition Facts & Serving Sizes
Per 1 cup (243g)
Per 100g
Source: USDA FoodData Central, SR Legacy, March 2026.
Kefir is a fermented dairy drink made by adding kefir grains to milk, producing a tangy, probiotic-rich beverage with 43 calories per 100g. One cup (243g) provides about 105 calories, 9.2g of protein, 11.7g of carbs, and 2.4g of fat. The protein content of 3.8g per 100g is solid for a liquid food and comes primarily from dairy casein and whey. Kefir stands out for its probiotic content, containing multiple strains of beneficial bacteria and yeasts not typically found in regular yogurt. It also delivers 130mg of calcium per 100g, 105mg of phosphorus, 164mg of potassium, 0.3mcg of vitamin B12, and 171mcg RAE of vitamin A. The fermentation process partially breaks down lactose, making kefir more tolerable than regular milk for many people who are lactose sensitive.
Nutrition Highlights
Calories by Serving Size
| Serving | Cal | Protein | Carbs | Fat | Fiber |
|---|---|---|---|---|---|
| 1 bottle (971g) | 417.5 | 36.9g | 46.6g | 9.7g | 0g |
| 1 cup (243g) | 104.5 | 9.2g | 11.7g | 2.4g | 0g |
| 100g | 43 | 3.8g | 4.8g | 1g | 0g |
Track Kefir in CaloBurner
Snap a photo to log calories and macros instantly.
Full Nutrition Facts (per 100g)
| Nutrient | Amount | % Daily Value |
|---|---|---|
| Calories | 43 | 2% |
| Protein | 3.8g | 8% |
| Total Fat | 1g | 1% |
| Saturated Fat | 0.7g | 4% |
| Total Carbohydrates | 4.8g | 2% |
| Dietary Fiber | 0g | |
| Sugars | 4.6g | 9% |
| Sodium | 40mg | 2% |
| Cholesterol | 5mg | 2% |
Vitamins & Minerals (per 100g)
| Nutrient | Amount | % Daily Value |
|---|---|---|
| Saturated Fat | 0.7g | 0% |
| Cholesterol | 5mg | 2% |
| Calcium | 130mg | 10% |
| Potassium | 164mg | 3% |
| Vitamin A | 171mcg | 19% |
| Vitamin C | 0.2mg | 0% |
| Vitamin D | 1mcg | 5% |
| Vitamin B6 | 0.1mg | 6% |
| Vitamin B12 | 0.3mcg | 13% |
| Magnesium | 12mg | 3% |
| Phosphorus | 105mg | 8% |
| Zinc | 0.5mg | 5% |
| Selenium | 3.6mcg | 7% |
| Folate | 13mcg | 3% |
| Riboflavin (B2) | 0.1mg | 8% |
| Niacin (B3) | 0.2mg | 1% |
% Daily Values based on a 2,000 calorie diet (FDA reference).
Health Benefits of Kefir
Kefir is one of the most probiotic-rich foods available. Unlike standard yogurt which contains a few strains, kefir is fermented with kefir grains that contain dozens of bacterial and yeast strains. Regular consumption has been associated with improved gut microbiome diversity, better digestion, and reduced symptoms of irritable bowel syndrome. A healthy gut is increasingly linked to reduced systemic inflammation, better immune function, and improved nutrient absorption.
For muscle building and recovery, the 3.8g of protein per 100g (9.2g per cup) adds meaningfully to daily totals. Dairy protein contains all essential amino acids including leucine, which is the key amino acid that triggers muscle protein synthesis. The calcium content at 130mg per 100g supports bone health, which is critical for anyone doing heavy resistance training.
The vitamin B12 content (0.3mcg per 100g) supports healthy red blood cell production and nerve function. Phosphorus at 105mg per 100g works alongside calcium in bone and teeth mineralization. Selenium at 3.6mcg per 100g supports antioxidant enzyme activity and thyroid health.
Dietary Considerations
Kefir is gluten-free and suitable for most dietary approaches that include dairy. It is not vegan. Due to fermentation reducing lactose content, many lactose-intolerant individuals can tolerate kefir better than regular milk. It is not suitable for a strict keto diet in large amounts due to 4.8g of carbs per 100g, but a cup fits within most moderate low-carb approaches. Kefir is paleo-controversial since many paleo frameworks exclude dairy. Look for plain, unsweetened kefir to avoid added sugars that are common in flavored varieties. Full-fat versions provide more calories and fat than the low-fat option reflected in this data.
Daily Intake (100g)
100g of kefir provides 2% of a 2,000-calorie diet.
Track Your Intake
See how kefir fits your personal calorie and macro targets.
Related Foods
Frequently Asked Questions
How many calories in kefir?
Kefir contains 43 calories per 100g. One cup (243g) has about 105 calories. It is a relatively low-calorie beverage compared to whole milk or flavored yogurt drinks, while providing solid protein content.
Is kefir good for weight loss?
Yes. Kefir is low in calories (43 per 100g), high in protein (3.8g per 100g), and contains probiotics that support gut health. Protein is satiating and helps preserve muscle during a calorie deficit. The probiotic strains in kefir may also positively influence metabolic health and body composition over time.
How much protein is in kefir?
Kefir contains 3.8g of protein per 100g. One cup (243g) provides 9.2g of protein. This is a solid amount for a liquid food and contributes to daily protein targets for muscle building and maintenance.
Is kefir good for gut health?
Yes, kefir is one of the best probiotic foods available. It contains a more diverse range of beneficial bacteria and yeasts than standard yogurt. Regular consumption is associated with improved gut microbiome diversity, better digestion, and reduced gut inflammation.
Can lactose-intolerant people drink kefir?
Many people with lactose intolerance can tolerate kefir better than regular milk. The fermentation process consumes a significant portion of the lactose, reducing its content. The live bacteria in kefir also produce lactase, which helps further break down lactose in the gut. Tolerance varies individually, so start with a small amount.
Is kefir better than yogurt?
Kefir and yogurt are both excellent fermented dairy products. Kefir typically contains a broader and more diverse range of probiotic strains due to the kefir grain fermentation process. Kefir is also a liquid, making it easy to consume as a drink. Greek yogurt tends to be higher in protein per serving. Both are excellent choices for gut health and protein intake.
Track Kefir in Your Diet
Snap a photo of your meal and CaloBurner will calculate the exact calories and macros. No food weighing required.