How the protein calculator works
The formula is simple: needs (g/day) = body weight (kg) × factor. The factor depends on your age and situation. For healthy adults aged 19 to 64, the German Nutrition Society (DGE) recommends 0.8 g of protein per kilogram of body weight per day, and from age 65 the estimate of 1.0 g/kg applies. Two examples:
- 70 kg, 30 years, everyday life: 70 × 0.8 = 56 g of protein per day
- 80 kg, strength training with the goal of building muscle: 80 × 1.4 to 80 × 2.0 = 112 to 160 g per day
The value from age 65 is explicitly declared an estimate by the DGE, because the needs of older adults cannot be determined with the desired precision. Besides nitrogen balance, it also takes muscle protein synthesis and physical function in older age into account.
Reference values at a glance: grams of protein per kg of body weight
| Group | g/kg/day | Source |
|---|---|---|
| Adults, 19 to 64 years | 0.8 | DGE (D-A-CH reference value) |
| Adults from age 65 | 1.0 (estimate) | DGE (D-A-CH reference value) |
| Pregnant, 2nd trimester | 0.9 | DGE |
| Pregnant, 3rd trimester | 1.0 | DGE |
| Breastfeeding | 1.2 | DGE |
| Sports, more than 5 h of training/week | 1.2 to 2.0 | DGE position paper on sports nutrition 2020 |
| Muscle building and maintenance in people who train | 1.4 to 2.0 | ISSN position stand 2017 |
For pregnant and breastfeeding women, the DGE additionally gives absolute extra amounts: according to the DGE, about 7 g more per day in the 2nd trimester, 21 g in the 3rd trimester and 23 g while breastfeeding. Also discuss your diet during this time with your doctor or midwife.
Protein for muscle building: what do the DGE and ISSN say?
If you train up to 5 hours per week, the DGE sees no increased need: it stays at 0.8 g/kg. For more than 5 hours of training per week, the DGE position paper on sports nutrition (2020) gives a range of 1.2 to 2.0 g/kg per day, depending on training status and goal. Ambitious athletes can go up to 2 g/kg according to the paper, ideally spread over 3 to 4 servings per day; a bit more is possible short term, for example during weight loss with muscle maintenance.
The International Society of Sports Nutrition (ISSN) comes to a similar conclusion in its 2017 position: for building and maintaining muscle, 1.4 to 2.0 g/kg per day is sufficient for most people who train. Per meal, about 0.25 g/kg or 20 to 40 g of high-quality protein is considered sensible. The ISSN mentions higher amounts (2.3 to 3.1 g/kg) only for the special case of preserving lean mass during a dieting phase.
Is a lot of protein harmful for the kidneys?
For healthy kidneys, a higher protein intake is considered safe based on current research. A meta-analysis of 28 randomized trials with 1,358 participants (Devries et al. 2018) found no evidence that more protein worsens kidney function in the long term. The observed rise in filtration rate is considered a normal, reversible adaptation, not damage. A systematic review (Van Elswyk et al. 2018) and the DGE umbrella review from 2023 come to the same conclusion.
Two caveats remain important: the DGE position paper gives up to 2 g/kg as a practical upper limit for athletes and recommends having kidney function checked at very high intakes. And anyone with a known kidney condition should always clarify their protein amount with a doctor.
High-protein foods: how to cover your needs
Most people reach their needs with what ends up on the table anyway, without any powder. These average values help with planning:
| Food | Protein per 100 g |
|---|---|
| Chicken breast, raw, skinless | approx. 23 g (cooked approx. 30 g) |
| Low-fat quark | approx. 12 to 14 g |
| Tofu, plain/firm | approx. 12 to 16 g (depending on the variety, silken tofu much less) |
| Egg, whole | approx. 13 g |
| Lentils, cooked | approx. 9 g (dried approx. 24 g) |
With legumes and meat, always pay attention to the state: cooked lentils contain around 9 g per 100 g, dried ones about 24 g, because water is added during cooking. Tofu varies a lot by variety, silken tofu sits far below firm tofu. You will find everyday ideas with these ingredients in our recipes.
What to do with your result
The gram value gives you an orientation, and a few grams more or less do not matter. Spread your protein amount over several meals and combine animal and plant sources. Then watch how you get on with it. How many calories you need in total is what our calorie calculator shows you; whether your weight is in a favorable range is what you check with the BMI calculator. You will find clear background knowledge without diet myths in our nutrition basics. And if you want to restructure your eating habits, a nutrition coach near you or online can help.