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Protein Calculator: How Much Protein Per Day
Enter your body weight and choose the profile that fits you to see a daily protein range in grams, the amount per meal, and the calories that protein supplies. Includes a kidney caution and the sources behind each range.
Where the numbers come from
The Recommended Dietary Allowance (RDA) for healthy adults is 0.8 grams of protein per kilogram of body weight per day. It was set by the US Institute of Medicine to meet the needs of nearly all healthy adults and is the baseline for the general profile here. It is a minimum to avoid deficiency, not a target for optimal body composition.
- Older adults (65+): the PROT-AGE study group suggested 1.0 to 1.2 g/kg a day, because ageing muscle responds less to protein and illness raises needs.
- Endurance training: 1.2 to 1.4 g/kg, in line with the joint position of the Academy of Nutrition and Dietetics, Dietitians of Canada and the American College of Sports Medicine.
- Strength and muscle gain: 1.4 to 2.0 g/kg, the range given in the International Society of Sports Nutrition position stand.
Which body weight to use
The calculator uses the weight you enter without adjusting it. For people with a lot of body fat to lose, using actual weight can overstate needs, and some dietitians base targets on a healthy or goal weight instead. Try the ideal weight calculator or the healthy weight calculator for a reference, then enter that number in place of your current weight if your care team suggests it.
When you are cutting calories, protein needs tend to sit at the upper end of your range, since it helps preserve muscle. When you are very active but eating little, the effect is stronger. Total food energy still decides weight change.
Spreading protein through the day
Splitting the daily total across meals is a practical habit; many studies on muscle building use roughly 0.25 to 0.4 g/kg in a feeding, but the evidence for a strict per-meal ceiling is weak, and the daily total matters most. The per-meal row simply divides your range by the number of feedings you enter, so a 98 g target over four meals is about 25 g each. Food sources include meat, fish, eggs, dairy, legumes, tofu, nuts and grains. Plant-based eaters may aim near the top of their range because plant proteins are generally somewhat less digestible.
Kidney disease and other cautions
People with chronic kidney disease, a single kidney, or an unexplained drop in kidney function are often advised to limit protein, and the advice depends on the stage. Use the GFR calculator for learning only and speak with a clinician. Pregnant or breastfeeding women, children, teenagers, and people with liver disease or metabolic disorders have different needs. Protein powders are food supplements and are not required. This page is educational and not medical advice.
Worked example
A 70 kg person lifting weights four days a week spreads protein over four feedings.
Inputs
| Body weight | 70 |
|---|---|
| Weight unit | Kilograms |
| Profile | Strength or muscle gain |
| Meals or feedings per day | 4 |
| Do you have kidney disease or reduced kidney function? | No |
Result
Strength and muscle gain range: 1.4 to 2 g per kg of body weight.
| Body weight used | 70.0 kg |
|---|---|
| Per meal (4 meals) | 25 to 35 g |
| Energy from protein | 392 to 560 kcal |
| Reference: RDA at 0.8 g/kg | 56 g |
- Protein supplies about 4 kcal per gram.
Medical disclaimer: This tool is for education and general planning. It is not medical advice and does not diagnose any condition. If you are pregnant, under 18, have an eating-disorder history or a medical condition, speak to a doctor or registered dietitian before changing your diet or exercise.
Frequently asked questions
How much protein do I need per day?
The RDA for healthy adults is 0.8 grams per kilogram of body weight per day. Older adults and people who train regularly are commonly advised to eat more, with ranges up to about 2.0 g/kg for strength training.
Is too much protein bad for the kidneys?
In people with healthy kidneys, intakes within the usual sports ranges are not shown to cause kidney damage, but people with kidney disease may need to limit protein. If you are unsure about your kidneys, ask your doctor before raising intake.
How much protein can the body use in one meal?
There is no hard limit on absorption. Studies on muscle building point to about 0.25 to 0.4 g/kg per feeding as an efficient amount, but total daily protein matters more than exact meal sizes.
Should I use my current weight or goal weight?
Healthy-weight adults can use current weight. People with obesity may be advised to use a goal or adjusted weight. Your dietitian can recommend which one suits you.
Do vegetarians need more protein?
Plant proteins are on average slightly less digestible and may lack some amino acids, so people eating mostly plants often aim a little higher and eat a variety of sources across the day.
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References and sources
- Institute of Medicine (2005). Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. National Academies Press (protein RDA 0.8 g/kg).
- Bauer J, et al. (2013). Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group. Journal of the American Medical Directors Association 14(8):542-559.
- Thomas DT, Erdman KA, Burke LM (2016). Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance.
- Jager R, et al. (2017). International Society of Sports Nutrition Position Stand: protein and exercise. Journal of the International Society of Sports Nutrition 14:20.