# Protein intake calculator

> Daily protein intake in grams from body weight, goal and training level, using published g/kg ranges, with a per-meal split.

Interactive version: https://www.calcopenly.com/health/protein-intake-calculator
Subject: Health and fitness calculators

Daily protein is body weight in kilograms times a grams-per-kilogram figure taken from published ranges for your goal and training. The adult RDA is 0.8 g/kg; athletes are advised 1.2–2.0 g/kg (ACSM, Academy of Nutrition and Dietetics and Dietitians of Canada, 2016); higher ranges apply during fat loss and muscle building. The target is the midpoint of the range, divided evenly across your meals.

People use it to plan meals around training or a diet. A 70 kg adult who exercises regularly gets 1.2–1.6 g/kg, or 84 to 112 g a day, with a 98 g target of about 25 g at each of 4 meals.

The RDA is a population figure set to cover 97–98 % of healthy adults. From age 65 the PROT-AGE group's minimum of 1.0–1.2 g/kg replaces it. People with kidney disease are usually given separate protein limits by their care team.

## Inputs

- **Weight**
- **Goal** (options: Lose fat, Maintain, Build muscle)
- **Exercise** (options: Little or none, Regular, Hard training)
- **Age**: From 65, the PROT-AGE minimum of 1.0–1.2 g/kg applies
- **Meals per day**

## Results

- Daily protein target (g/day) — main result
- Range from (g/day)
- Range to (g/day)
- Range from (per kg) (g/kg)
- Range to (per kg) (g/kg)
- Protein per meal (g)
- Calories from protein (kcal/day)

## Formula

$$
\text{protein (g/day)} = \text{weight (kg)} \times \text{g/kg},\qquad \text{target} = \text{weight} \times \frac{\text{low} + \text{high}}{2}
$$

## Worked examples

### Sedentary adult at the RDA

- Weight: 70 kg
- Goal: Maintain
- Exercise: Little or none
- Age: 30 years
- Meals per day: 4
- **Daily protein target: 56 g/day**
- **Range from: 56 g/day**
- **Range to: 56 g/day**
- **Protein per meal: 14 g**
- **Calories from protein: 224 kcal/day**
- Checked against: IOM RDA 0.8 g/kg × 70 kg = 56 g; ÷ 4 meals; × 4 kcal/g

### Building muscle with hard training

- Weight: 80 kg
- Goal: Build muscle
- Exercise: Hard training
- Age: 25 years
- Meals per day: 4
- **Range from: 152 g/day**
- **Range to: 176 g/day**
- **Daily protein target: 164 g/day**
- **Protein per meal: 41 g**
- Checked against: Python 3.8 decimal: upper half of Morton 2018's 1.6–2.2 g/kg = 1.9–2.2 × 80 kg; midpoint 2.05 × 80

### Losing fat with regular exercise

- Weight: 90 kg
- Goal: Lose fat
- Exercise: Regular
- Age: 40 years
- Meals per day: 3
- **Range from: 162 g/day**
- **Range to: 203 g/day**
- **Daily protein target: 182 g/day**
- **Protein per meal: 61 g**
- Checked against: Python 3.8 decimal: lower half of Phillips & Van Loon's 1.8–2.7 g/kg = 1.8–2.25 × 90 kg

### Edge: 70-year-old raised to the PROT-AGE minimum

- Weight: 60 kg
- Goal: Maintain
- Exercise: Little or none
- Age: 70 years
- Meals per day: 3
- **Range from (per kg): 1 g/kg**
- **Range to (per kg): 1.2 g/kg**
- **Range from: 60 g/day**
- **Range to: 72 g/day**
- **Daily protein target: 66 g/day**
- Checked against: PROT-AGE (Bauer 2013): at least 1.0–1.2 g/kg for adults 65+, replacing 0.8; × 60 kg

### Pounds: 150 lb, losing weight without exercise

- Weight: 150 lb
- Goal: Lose fat
- Exercise: Little or none
- Age: 35 years
- Meals per day: 4
- **Range from: 82 g/day**
- **Range to: 109 g/day**
- **Daily protein target: 95 g/day**
- Checked against: Python 3.8 decimal: 150 lb = 68.0389 kg × Leidy 2015's 1.2–1.6 g/kg

## Questions

### How much protein do I need per day?

The US and Canadian RDA for adults is 0.8 g per kg of body weight, set to cover the needs of 97–98 % of healthy people: 56 g a day for a 70 kg adult. It is a floor that prevents deficiency, not a ceiling. Guidance for other groups is higher: 1.2–2.0 g/kg for athletes (ACSM 2016) and at least 1.0–1.2 g/kg for adults over 65 (PROT-AGE 2013).

### How much protein do you need to build muscle?

About 1.6 g per kg a day. A 2018 meta-analysis of 49 trials with 1,863 participants (Morton and colleagues) found that extra protein stopped adding fat-free mass beyond a total intake of 1.62 g/kg, with 2.2 g/kg as the upper confidence limit. For an 80 kg person that is 130 to 176 g a day. The gains came with resistance training; protein alone does not build muscle.

### How much protein can the body use in one meal?

More than the often-quoted 20–25 g, though higher doses are increasingly oxidised for energy. Schoenfeld and Aragon (2018) concluded that muscle building is best served by about 0.4 g/kg per meal over at least four meals, reaching at least 1.6 g/kg a day, and at most about 0.55 g/kg per meal at 2.2 g/kg a day. For a 70 kg person, 0.4 g/kg is 28 g per meal.

### How much protein should you eat when losing weight?

More than the RDA. A 2015 review by Leidy and colleagues supports 1.2–1.6 g/kg a day for weight loss and maintenance, and Phillips and Van Loon (2011) proposed 1.8–2.7 g/kg for athletes in an energy deficit to limit muscle loss. For a 90 kg person training regularly, the lower half of that athletic range is 162 to 203 g a day.

### How accurate is the protein intake calculator?

Accuracy depends on your inputs and the method's assumptions. Decimal arithmetic uses 50 significant digits, but estimates, numerical methods and source data can be less precise; the displayed rounding does not remove those limits. It is checked against 5 worked examples whose answers come from independent sources; for example, “Sedentary adult at the RDA” is checked against IOM RDA 0.8 g/kg × 70 kg = 56 g; ÷ 4 meals; × 4 kcal/g.

### Where does the method come from?

Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2005); Thomas DT, Erdman KA, Burke LM. ACSM/AND/DC joint position: Nutrition and athletic performance. Med Sci Sports Exerc 2016;48:543–568; Leidy HJ et al. The role of protein in weight loss and maintenance. Am J Clin Nutr 2015;101:1320S–1329S; Phillips SM, Van Loon LJC. Dietary protein for athletes: from requirements to optimum adaptation. J Sports Sci 2011;29 Suppl 1:S29–S38; Morton RW et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains. Br J Sports Med 2018;52:376–384; Bauer J et al. Evidence-based recommendations for optimal dietary protein intake in older people (PROT-AGE). J Am Med Dir Assoc 2013;14:542–559; Schoenfeld BJ, Aragon AA. How much protein can the body use in a single meal for muscle-building? J Int Soc Sports Nutr 2018;15:10.

## Sources

- [Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2005)](https://nap.nationalacademies.org/catalog/10490)
- Thomas DT, Erdman KA, Burke LM. ACSM/AND/DC joint position: Nutrition and athletic performance. Med Sci Sports Exerc 2016;48:543–568
- Leidy HJ et al. The role of protein in weight loss and maintenance. Am J Clin Nutr 2015;101:1320S–1329S
- [Phillips SM, Van Loon LJC. Dietary protein for athletes: from requirements to optimum adaptation. J Sports Sci 2011;29 Suppl 1:S29–S38](https://pubmed.ncbi.nlm.nih.gov/22150425/)
- Morton RW et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training-induced gains. Br J Sports Med 2018;52:376–384
- Bauer J et al. Evidence-based recommendations for optimal dietary protein intake in older people (PROT-AGE). J Am Med Dir Assoc 2013;14:542–559
- Schoenfeld BJ, Aragon AA. How much protein can the body use in a single meal for muscle-building? J Int Soc Sports Nutr 2018;15:10

_Note: medical information, not professional advice._