Daily protein has two answers: the amount that prevents a shortfall and the amount that fits your training
How much protein you need each day depends on what you are asking. One answer is the national reference intake, meant to keep nearly everyone from falling short: the US Recommended Dietary Allowance of 0.8 g per kg of body weight, which works out to 56 g a day for a reference man (70 kg) and 46 g for a reference woman (57 kg). The other is a set of per-kilogram ranges that sports and aging researchers recommend for building or keeping muscle, running from 1.0 up to 3.1 g per kg depending on your situation.
The calculator above takes your weight, age, sex and situation, picks the guideline that fits, and shows a daily amount and a per-meal amount. It also lines up the different guidelines side by side for the same body weight. It uses each organization's published range as written, with no hidden multipliers.
How to use the calculator
- Enter sex, weight and age: weight can be in lb or kg. People under 19 have separate growth-stage needs and are not calculated.
- Choose your situation: pick "little or no exercise" for a typical adult, or the option that matches your training type and goal. From age 65 the older-adult recommendation is applied automatically.
- Read the result: you get the daily amount, grams per kg, grams per meal, the US RDA and calories, plus bars that compare the other guidelines.
- Log what you eat: add protein in grams or tap a common food to see how much is left to your target. The log stays in this browser only if you switch saving on.
The US RDA for protein
The Recommended Dietary Allowance for adults, set by the Institute of Medicine (now part of the National Academies) in 2005, is 0.8 g of protein per kg of body weight per day. It applies to every adult age and to men and women alike, and it is the amount that covers the needs of almost everyone, not an average. Protein is also expected to supply 10–35% of daily energy (the Acceptable Macronutrient Distribution Range).
| Body weight | US RDA 0.8 g/kg (g/day) |
|---|---|
| 50 kg | 40 |
| 60 kg | 48 |
| 70 kg | 56 |
| 80 kg | 64 |
| 90 kg | 72 |
Needs rise during pregnancy and breastfeeding. If that applies to you, follow the advice of your doctor or midwife rather than a general calculator.
Daily protein by body weight
Each guideline that uses a per-kg range, worked out for several body weights (grams, rounded).
| Body weight | Safe level 0.83 g/kg | Age 65+ 1.0–1.2 | Regular exercise 1.2–2.0 | Strength training 1.4–2.0 | Strength + cutting 2.3–3.1 |
|---|---|---|---|---|---|
| 50 kg (110 lb) | 42 | 50–60 | 60–100 | 70–100 | 115–155 |
| 60 kg (132 lb) | 50 | 60–72 | 72–120 | 84–120 | 138–186 |
| 70 kg (154 lb) | 58 | 70–84 | 84–140 | 98–140 | 161–217 |
| 80 kg (176 lb) | 66 | 80–96 | 96–160 | 112–160 | 184–248 |
| 90 kg (198 lb) | 75 | 90–108 | 108–180 | 126–180 | 207–279 |
For example, a 70 kg (154 lb) person who lifts three or four times a week could plan on 98–140 g a day, split into meals of 18–21 g (0.25–0.3 g/kg) every 3–4 hours.
Why the guidelines give different numbers
- The US RDA (0.8 g/kg) and the WHO figure (0.83 g/kg): both come from the amount needed to keep nitrogen balance, plus a margin for individual differences. They mark the level below which you may fall short; they were not set with training or muscle gain in mind.
- 1.0–1.2 g/kg for ages 65 and over: the PROT-AGE expert group recommends this range to slow muscle loss, and at least 1.2 g/kg for older adults who exercise.
- 1.2–2.0 g/kg for exercise: the 2016 joint position of the American College of Sports Medicine, the Academy of Nutrition and Dietetics and Dietitians of Canada, which also suggests about 0.3 g/kg after training and every 3–5 hours.
- 1.4–2.0 g/kg for strength training, 2.3–3.1 g/kg while cutting: the 2017 position stand of the International Society of Sports Nutrition (ISSN), which suggests 0.25 g/kg or 20–40 g per serving, spread every 3–4 hours.
How much food gives 20 g of protein
Calculated from the protein per 100 g in USDA FoodData Central. The same food varies by cut, cooking method and brand, so trust the nutrition label on the package first.
| Food | Protein per 100 g | Amount for 20 g |
|---|---|---|
| Roasted chicken breast (skinless) | 31.0 g | about 65 g |
| Cooked farmed salmon | 22.1 g | about 90 g |
| Firm tofu | 17.3 g | about 116 g |
| Egg (one large egg is 50 g) | 12.6 g | about 3 eggs |
| Greek yogurt (nonfat, plain) | 10.2 g | about 196 g |
Common mistakes
- Using the RDA as a training target: the RDA is the line that prevents a shortfall. If you strength-train, aiming for 1.4 g/kg or more matches the recommendations.
- Applying the cutting range to everyone: 2.3–3.1 g/kg is advised only for people who lift while reducing calories.
- Eating it all in one meal: the ISSN suggests spreading the day's total evenly every 3–4 hours.
- Confusing food weight with protein weight: 100 g of chicken breast holds about 31 g of protein, not 100 g.
- Following a high-protein plan with kidney disease: for non-dialysis chronic kidney disease in stages 3–5, the KDOQI 2020 guideline suggests going down to 0.55–0.6 g/kg instead.
Limitations and cautions
- Illness, recovery from surgery, pregnancy, breastfeeding and growth under age 19 are outside what this calculator covers. If a doctor or dietitian gave you a target, follow that.
- The per-kg ranges use actual body weight. With obesity, an amount based on actual weight can be too high, so it is wise to talk to a professional.
- Where you land within a range depends on how much you train and what you are aiming for. The calculator shows organizational recommendations; it does not prescribe for an individual.
- The log of what you ate stays in this browser only if you turn saving on, and it is never sent to a server.
As of the sources were checked on 2026-10-09.
Sources
- 01National Academies of Sciences, Engineering, and Medicine: Dietary Reference Intakes for protein (IOM 2005)RDA 0.8 g/kg/day; 56 g/day for a 70 kg reference man and 46 g/day for a 57 kg reference woman
- 02ISSN Position Stand: Protein and Exercise (Jäger et al., 2017)1.4–2.0 g/kg for people who train, 2.3–3.1 g/kg while cutting, 0.25 g/kg or 20–40 g per serving
- 03ACSM, AND and DC: Nutrition and Athletic Performance (2016)1.2–2.0 g/kg for athletes, 0.3 g/kg after exercise and every 3–5 hours
- 04PROT-AGE Study Group (Bauer et al., 2013)1.0–1.2 g/kg for ages 65 and over, at least 1.2 g/kg for older adults who exercise
- 05EFSA: Dietary Reference Values for protein (2012)Adult PRI 0.83 g/kg (same as the WHO/FAO/UNU 2007 safe level)
- 06USDA FoodData Central (SR Legacy)Protein per 100 g of food (FDC 171477, 175168, 172475, 171287, 170894)
- 07KDOQI Clinical Practice Guideline for Nutrition in CKD (2020)0.55–0.6 g/kg for non-dialysis CKD stages 3–5
- 08Acceptable Macronutrient Distribution Ranges (National Academies)Protein 10–35% of daily energy
Frequently asked questions
How much protein should I eat per day?
The US RDA is 0.8 g per kg of body weight a day, which is 56 g for a 70 kg man and 46 g for a 57 kg woman. It is the amount meant to keep nearly everyone from falling short. If you train, guidelines advise more, such as 1.2–2.0 g per kg.
How many grams of protein per kg of body weight do I need?
Adults who barely exercise do well on 0.8 g (US RDA) to 0.83 g (WHO, FAO and UNU). Ages 65 and over are advised 1.0–1.2 g, regular exercise 1.2–2.0 g and strength training 1.4–2.0 g. One position stand goes up to 2.3–3.1 g while cutting calories and lifting.
How much protein do I need to build muscle?
The International Society of Sports Nutrition (ISSN, 2017) considers 1.4–2.0 g per kg enough for most people who train. At 70 kg that is 98–140 g a day, taken as 0.25 g per kg or 20–40 g per serving about every 3–4 hours.
How much protein should I eat in one meal?
The ISSN suggests 0.25 g per kg or 20–40 g per serving, and ACSM and others suggest 0.3 g per kg. At 70 kg that is 18–21 g a meal. About 65 g of roasted chicken breast or 3 large eggs gets you near 20 g.
Do I need more protein as I get older?
The PROT-AGE group recommends 1.0–1.2 g per kg for ages 65 and over, and at least 1.2 g for older adults who exercise. That is higher than the 0.8 g per kg US RDA, which is set for adults of all ages and meets the needs of nearly all adults.
Should I eat more protein when dieting?
For people who lift while cutting calories, the ISSN (2017) says 2.3–3.1 g per kg may be needed to protect muscle. That evidence does not cover simply eating less without exercise, so do not apply the range to a crash diet.
Is a lot of protein bad for my kidneys?
With kidney disease, guidelines advise less protein. The KDOQI 2020 guideline suggests 0.55–0.6 g per kg for non-dialysis chronic kidney disease in stages 3–5. If you have or suspect kidney disease, follow your doctor rather than the calculator.
How many calories are in a gram of protein?
One gram of protein provides about 4 kcal, so 100 g a day supplies roughly 400 kcal. US guidance expects protein to supply 10–35% of daily calories.