Protein is the nutrient most associated with muscle, but it also builds enzymes, hormones, skin, hair and the immune system, and the body cannot store it the way it stores fat. You need a steady supply every day. How much depends on your size and your stage of life: expert bodies publish different figures for typical adults, older adults, athletes, and for women who are pregnant or breastfeeding. This calculator applies those published figures to your body weight and divides the total over your meals.
The numbers are population guidance, not a personal prescription. If you have kidney disease or another medical condition, follow the advice of your clinician.
How to use the protein calculator
- Enter your body weight in kilograms or pounds.
- Select the group that applies to you: typical adult, over 65, athlete or very active, pregnant or breastfeeding.
- Set your meals per day to see grams per meal.
- Read the daily range. Where guidance gives a range, the low and high ends are shown.
Protein formula
Per meal (g) = daily protein ÷ meals
| Group | Grams per kg per day | Source |
|---|---|---|
| Typical adult | 0.8 | Institute of Medicine, Dietary Reference Intakes, 2005 (RDA) |
| Adults aged 65 and over | 1.0 – 1.2 | PROT-AGE Study Group, Bauer et al., J Am Med Dir Assoc 2013;14:542–559 |
| Athletes and very active people | 1.2 – 2.0 | Academy of Nutrition and Dietetics, Dietitians of Canada, ACSM, 2016 |
| Pregnancy | 1.1 | Institute of Medicine, 2005 (RDA) |
| Breastfeeding | 1.3 | Institute of Medicine, 2005 (RDA) |
Worked example
A 75 kg adult aged 70, eating 3 meals a day.
- Low end: 75 × 1.0 = 75 g a day
- High end: 75 × 1.2 = 90 g a day
- Per meal: 75 ÷ 3 to 90 ÷ 3 = 25–30 g
- For comparison, the adult RDA would be 75 × 0.8 = 60 g.
Daily protein by body weight
| Body weight | Adult RDA 0.8 g/kg (g/day) | Older adult 1.0–1.2 g/kg (g/day) | Athlete 1.2–2.0 g/kg (g/day) |
|---|---|---|---|
| 50 kg (110 lb) | 40 | 50–60 | 60–100 |
| 60 kg (132 lb) | 48 | 60–72 | 72–120 |
| 70 kg (154 lb) | 56 | 70–84 | 84–140 |
| 80 kg (176 lb) | 64 | 80–96 | 96–160 |
| 90 kg (198 lb) | 72 | 90–108 | 108–180 |
| 100 kg (220 lb) | 80 | 100–120 | 120–200 |
What protein looks like in food
- Animal sources such as eggs, dairy, fish, poultry and meat contain all the essential amino acids.
- Plant sources such as beans, lentils, tofu, nuts and whole grains can meet needs when eaten in variety.
- Portions add up. Check food labels for grams of protein per serving rather than relying on rough estimates.
- Calories still count. Protein supplies 4 kcal per gram, so a 100 g daily intake adds 400 kcal to your day; see the Macro Calculator.
Who needs to be careful
People with chronic kidney disease, liver disease or certain metabolic disorders may be advised to limit protein, and others may need more after surgery or during illness. The ranges here assume a healthy adult. Anyone with a medical condition, a history of eating disorders, or who is pregnant should discuss targets with a doctor or dietitian. For related tools see the Calorie Calculator, the TDEE Calculator and the Lean Body Mass Calculator.
This page is for information only and is not medical or dietary advice. Speak to a doctor or registered dietitian about your own needs.
Sources
- Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. National Academies Press, 2005.
- Bauer J, et al. Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group. J Am Med Dir Assoc 2013;14:542–559.
- Thomas DT, Erdman KA, Burke LM. Position of the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance. J Acad Nutr Diet 2016;116:501–528.
Frequently asked questions
How much protein do I need per day?
The US Recommended Dietary Allowance for healthy adults is 0.8 grams per kilogram of body weight, which is 56 g a day for a 70 kg person. That is the amount that meets the needs of most people to avoid deficiency. Some groups, such as older adults and athletes, are advised to eat more.
Do older adults need more protein?
Many expert groups say so. The PROT-AGE Study Group (Bauer et al., J Am Med Dir Assoc 2013;14:542–559) recommended 1.0–1.2 g/kg per day for healthy people over 65 to help preserve muscle, and more for those with illness, subject to medical advice.
How much protein do athletes need?
The joint position of the Academy of Nutrition and Dietetics, Dietitians of Canada and the American College of Sports Medicine (2016) puts the range for athletes at 1.2 to 2.0 g/kg per day, with the amount depending on the sport, training load and calorie intake.
Is a high-protein diet safe?
Intakes within the Acceptable Macronutrient Distribution Range of up to 35 percent of calories are considered acceptable for healthy adults. People with kidney disease or other conditions may need to limit protein and should follow their clinician’s advice.
Why divide protein across meals?
Spreading protein over the day, often 20 to 40 g per meal, is common advice for supporting muscle repair. It is not essential to hit a specific amount at each meal, but the per-meal figures help with planning.