Enter your numbers
6 questions. Questions that only apply to some people appear once your earlier answers decide that they do.
From your health data
5 of these questions can be answered from lab results and device data you have already connected: Body weight, Age, Do you do resistance training at least twice a week?, Body fat, if you know it, Do you have chronic kidney disease at stage 3 or worse (eGFR under 60)?. Connect them once in your member account and they arrive here pre-filled and labelled as coming from your health data — and you can always type over the value.
Set up health data in your member account
This public page never reads your health data. Pre-filling happens inside the signed-in app, which is a separate, access-controlled surface.
How this is calculated
Formula version lll-protein-1.0.0
The goal selects a published range, which is then multiplied by body weight — or, for fat loss with a known body-fat percentage in a resistance-trained person, by fat-free mass, because that is the basis the source states. Maintenance uses the ISSN range of 1.4-2 g/kg/day for active people and Phillips & Van Loon's 1.3-1.8 otherwise. Muscle gain runs from Morton's breakpoint of 1.62 to the top of its confidence interval, 2.2. Fat loss uses Helms' 2.3-3.1 g/kg fat-free mass where possible, otherwise Phillips & Van Loon's 1.8-2 g/kg body weight. Age 65 and over raises the floor to the PROT-AGE and ESPEN minimum. A declared CKD stage 3 or worse overrides everything with the KDIGO target of 0.8 g/kg/day.
What it cannot do
- The most-quoted fat-loss range is per kilogram of fat-free mass; sources routinely misquote it per kilogram of body weight. This calculator states which basis it used, but the underlying ambiguity is real.
- Morton's breakpoint was not statistically significant (p = 0.079) and its confidence interval spans 1.03-2.20 g/kg/day.
- The Helms recommendation was derived in lean, resistance-trained athletes and does not transfer to untrained people with higher body fat.
- ESPEN gives no figure for the severe-illness tier; the 2.0 g/kg/day figure is PROT-AGE only.
- The KDIGO recommendation is graded 2C, weak with low-quality evidence, and the harm evidence above 1.3 g/kg/day is observational.
- Protein quality, leucine content and distribution all matter and are only partly represented by a per-meal figure.
Sources
- Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. National Academies Press; 2005DOI 10.17226/10490 (opens in a new tab)
- Jager R et al. ISSN Position Stand: protein and exercise. J Int Soc Sports Nutr 2017;14:20DOI 10.1186/s12970-017-0177-8 (opens in a new tab)PMID 28642676 (opens in a new tab)
- Morton RW et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains in muscle mass and strength. Br J Sports Med 2018;52(6):376-384DOI 10.1136/bjsports-2017-097608 (opens in a new tab)PMID 28698222 (opens in a new tab)
- Helms ER et al. A systematic review of dietary protein during caloric restriction in resistance trained lean athletes. Int J Sport Nutr Exerc Metab 2014;24(2):127-138DOI 10.1123/ijsnem.2013-0054 (opens in a new tab)PMID 24092765 (opens in a new tab)
- Phillips SM, Van Loon LJC. Dietary protein for athletes: from requirements to optimum adaptation. J Sports Sci 2011;29(S1):S29-S38DOI 10.1080/02640414.2011.619204 (opens in a new tab)PMID 22150425 (opens in a new tab)
- Bauer J et al. PROT-AGE Study Group position paper. J Am Med Dir Assoc 2013;14(8):542-559DOI 10.1016/j.jamda.2013.05.021 (opens in a new tab)PMID 23867520 (opens in a new tab)
- Deutz NEP et al. Protein intake and exercise for optimal muscle function with aging: ESPEN Expert Group recommendations. Clin Nutr 2014;33(6):929-936DOI 10.1016/j.clnu.2014.04.007 (opens in a new tab)PMID 24814383 (opens in a new tab)
- KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int 2024;105(4S):S117-S314DOI 10.1016/j.kint.2023.10.018 (opens in a new tab)
The formula version is pinned so that a result you saved or shared can be reproduced. When we change a coefficient, the version changes and old results stay attributed to the version that produced them.
Questions people ask
- Why is the target higher than the official recommendation?
- The official minimum is set to prevent deficiency in most people, which is a different question from what optimises lean mass retention with age. The tool shows both and says which is which.
- Do I need supplements to hit it?
- Usually not. The number is achievable from food for most people at most targets, and protein powder is a convenience rather than a requirement. We have no commercial reason to tell you otherwise.
- What if I have kidney disease?
- Then protein intake is a clinical decision and this tool is the wrong input to it. High intake is not harmful to healthy kidneys, but in established kidney disease the target is set by your nephrologist, not by a calculator.