Free tool · Cantein Research
Protein Calculator
How much protein do you need a day? Enter your weight, age, and goal to get a daily protein intake in grams, how much to eat at each meal, and the research behind each number.
Step 2
Your protein target
Enter your age and weight to see how much protein you need a day.
Quick answer
How much protein do I need a day?
Most healthy adults do well with 1.2–1.6 g of protein per kilogram of body weight a day, or about 0.54–0.73 g per pound. For a 170 lb adult, that is about 93–123 g a day. If you strength train, especially while losing weight, you can go higher.
The RDA is 0.8 g per kg: 56 g a day for the reference man and 46 g for the reference woman. That figure is set to prevent deficiency in nearly all healthy adults. It isn’t a target for keeping muscle, recovering from exercise, or losing fat, which is why research on those goals lands higher (Phillips et al., 2016).
Methodology
Protein intake targets by goal
Your target is grams of protein per kilogram of body weight, chosen by goal. The calculator uses the same targets as our amino acid calculator.
| Goal | Target | Range | Basis |
|---|---|---|---|
| Stay healthy, mostly sedentary | 1.2 g/kg | 1.2–1.6 g/kg | Intakes above the RDA support muscle and metabolic health (Phillips et al., 2016) |
| Stay healthy, active | 1.4 g/kg | 1.4–2.0 g/kg | ISSN position stand for exercising adults (Jäger et al., 2017) |
| Lose weight | 1.6 g/kg | 1.2–1.6 g/kg | Review of weight-loss trials (Leidy et al., 2015). We use the top of the range. |
| Build or keep muscle | 1.6 g/kg | 1.6–2.2 g/kg | Muscle gains plateau near 1.6 g/kg in a meta-analysis of 49 trials (Morton et al., 2018) |
| Lose fat while lifting | 2.2 g/kg | 2.0–2.6 g/kg | ISSN: 2.3–3.1 g/kg of lean mass while in a calorie deficit |
| Age 65+ | At least 1.2 g/kg | 1.0–1.5 g/kg | 1.0–1.2 g/kg for healthy older adults, more with exercise or illness (PROT-AGE, Bauer et al., 2013; ESPEN, Deutz et al., 2014) |
Lean-mass adjustment
Protein needs follow lean mass, not fat mass. If you enter a body fat above 25%, the calculator uses your lean mass divided by 0.75: the weight you would be at 25% body fat with your current muscle. If you leave body fat blank, it uses your total weight.
Losing weight? Our protein calculator for weight loss covers what the research shows and how to set a target with more weight to lose.
Reference
Protein intake by body weight
Grams of protein a day, using total body weight.
| Weight | RDA minimum (0.8 g/kg) | Mostly sedentary (1.2 g/kg) | Active (1.4 g/kg) | Losing weight or lifting (1.6 g/kg) | Lifting in a deficit (2.2 g/kg) |
|---|---|---|---|---|---|
| 120 lb (54 kg) | 44 g | 65 g | 76 g | 87 g | 120 g |
| 140 lb (64 kg) | 51 g | 76 g | 89 g | 102 g | 140 g |
| 160 lb (73 kg) | 58 g | 87 g | 102 g | 116 g | 160 g |
| 180 lb (82 kg) | 65 g | 98 g | 114 g | 131 g | 180 g |
| 200 lb (91 kg) | 73 g | 109 g | 127 g | 145 g | 200 g |
| 220 lb (100 kg) | 80 g | 120 g | 140 g | 160 g | 220 g |
| 240 lb (109 kg) | 87 g | 131 g | 152 g | 174 g | 239 g |
| 260 lb (118 kg) | 94 g | 142 g | 165 g | 189 g | 259 g |
At higher body weights, these totals can overstate what you need, because fat mass needs little protein. Entering a body fat estimate in the calculator gives a lean-mass-based number.
Conversions
Protein per pound of body weight
| Goal | Per kg | Per lb |
|---|---|---|
| RDA minimum | 0.8 g | 0.36 g |
| Mostly sedentary | 1.2 g | 0.54 g |
| Active | 1.4 g | 0.64 g |
| Losing weight or lifting | 1.6 g | 0.73 g |
| Lifting in a deficit | 2.2 g | 1.0 g |
The popular rule of 1 g of protein per pound of body weight matches the highest target here, lifting in a calorie deficit. For most other goals, the research ranges are lower.
Men and women
Protein for men and women
Official protein targets are set per kilogram of body weight, and the RDA of 0.8 g per kg is the same for men and women (Institute of Medicine). Men’s RDA of 56 g a day is higher than women’s 46 g because it is based on a heavier reference body weight. Because this calculator works per kilogram, a man and a woman of the same weight and goal get the same target.
For questions specific to women, like menopause and pregnancy, see our protein calculator for women.
Age
Protein by age: under 65 and 65+
| Age | RDA | Research-based target | Per main meal |
|---|---|---|---|
| 19–64 | 0.8 g/kg | 1.2–1.6 g/kg by goal, more if you lift | About 0.3 g/kg, or 0.4 g/kg if you strength train |
| 65 and older | 0.8 g/kg | At least 1.0–1.2 g/kg, more with exercise or illness | About 0.4 g/kg |
The RDA is the same 0.8 g per kg for every adult 19 and older. Expert groups recommend more from 65, because older muscle needs more protein in a meal to respond the same way (Moore et al., 2015). Our guides to protein after 50 without dairy and protein powder after 50 cover the per-meal numbers in more detail.
Meals
How much protein per meal
Muscle protein synthesis responds to each meal, not just the daily total. Aim for about 0.3 g per kg in each main meal, or 0.4 g per kg if you strength train or are 65 or older, then spread the rest of your target across meals and snacks (Schoenfeld & Aragon, 2018; Moore et al., 2015). For a 170 lb adult, that is about 23 g per meal, or 31 g if you lift.
Our amino acid calculator checks each meal you log for protein and leucine, the amino acid that triggers the muscle response, and a full day against all nine essential amino acids.
Pregnancy
Pregnancy and breastfeeding
The RDA rises to 71 g a day in pregnancy and while breastfeeding (Institute of Medicine). This calculator isn’t designed for pregnancy, so ask your doctor or midwife for a personal target.
FAQ
Frequently asked questions
How much protein do I need a day?
Most healthy adults do well with 1.2–1.6 g of protein per kg of body weight a day, or about 0.54–0.73 g per pound. For a 170 lb adult, that is about 93–123 g a day. The RDA of 0.8 g per kg is a minimum to prevent deficiency, not an optimal intake.
How many grams of protein per pound should I eat?
About 0.54–0.73 g per pound of body weight for most goals, and up to 1 g per pound if you strength train while eating in a calorie deficit. The RDA works out to 0.36 g per pound.
How much protein do I need to build muscle?
In a meta-analysis of 49 trials, muscle gains from strength training plateaued at about 1.6 g of protein per kg a day (Morton et al., 2018), so the calculator uses 1.6 g per kg for building muscle. The study’s estimate ran as high as 2.2 g per kg, so some lifters aim higher.
How much protein should I eat to lose weight?
A review of weight-loss trials supports about 1.2–1.6 g of protein per kg a day (Leidy et al., 2015). If you lift while eating in a calorie deficit, sports nutrition guidance runs higher, so the calculator uses 2.2 g per kg for that goal. If you carry a lot of body fat, adding a body fat estimate gives a target based on lean mass instead.
How much protein should I eat per meal?
Muscle responds to each meal, not just the daily total. Aim for about 0.3 g per kg in each main meal, or 0.4 g per kg if you strength train or are 65 or older. For a 170 lb adult, that is about 23–31 g per meal.
Do men need more protein than women?
Not per kilogram. The RDA is 0.8 g per kg for both. Men’s RDA of 56 g a day is higher than women’s 46 g because it is based on a heavier reference body weight. At the same weight and goal, this calculator gives a man and a woman the same target.
How much protein do adults over 65 need?
The RDA doesn’t change with age: it stays at 0.8 g per kg. Expert groups recommend more from 65: 1.0–1.2 g per kg for healthy older adults, and more with exercise or illness (PROT-AGE, ESPEN). Getting enough protein at each meal matters more with age.
Does the calculator store my data?
No. It runs in your browser, and nothing you enter is sent to Cantein or saved.
Is this medical advice?
No. It is an educational estimate for healthy adults. If you have kidney disease, are pregnant or breastfeeding, or follow a medically prescribed diet, talk with your clinician before changing your protein intake.
Source library
Sources
- Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids.National Academies Press, 2005.
- Phillips, Chevalier & Leidy. Protein “requirements” beyond the RDA: implications for optimizing health.Applied Physiology, Nutrition, and Metabolism, 41(5), 2016.
- Jäger et al. International Society of Sports Nutrition position stand: protein and exercise.Journal of the International Society of Sports Nutrition, 14, 2017.
- Leidy et al. The role of protein in weight loss and maintenance.American Journal of Clinical Nutrition, 101(6), 2015.
- Morton 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.British Journal of Sports Medicine, 52(6), 2018.
- Bauer et al. 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), 2013.
- Deutz et al. Protein intake and exercise for optimal muscle function with aging: recommendations from the ESPEN Expert Group.Clinical Nutrition, 33(6), 2014.
- Moore et al. Protein ingestion to stimulate myofibrillar protein synthesis requires greater relative protein intakes in healthy older versus younger men.Journals of Gerontology: Series A, 70(1), 2015.
- Schoenfeld & Aragon. How much protein can the body use in a single meal for muscle-building?Journal of the International Society of Sports Nutrition, 15, 2018.
Not medical advice. This calculator gives educational estimates for healthy adults 18 and older. Talk with your clinician before changing protein intake if you have kidney disease, are pregnant or breastfeeding, or follow a medically prescribed diet. Cantein makes hemp protein powder. Corrections: info@cantein.com.