Why does protein need depend on weight and activity?
Protein is the raw material for building and repairing muscle, skin, enzymes and immune components. Your body breaks down and rebuilds some protein every day, and if food does not replace what is lost, tissue such as muscle is drawn on to make up the difference. The minimum amount that prevents this loss is called the requirement. A heavier body has more tissue to maintain, so the requirement scales with weight, which is why most guidelines are written as grams per kilogram of body weight per day (g/kg) rather than as a fixed total.
Training raises the amount of protein used to repair and adapt muscle fibres, and with age the muscle responds less strongly to the same protein intake (often called anabolic resistance), which is why recent international guidance tends to suggest more, not less, for active people and older adults. This calculator simplifies those differences into four activity levels and shows each as a range.
The formula and the four activity levels
Daily protein (g) = body weight (kg) Γ the g/kg range for the chosen activity level
| Activity level | Range applied (g/kg) | What the range represents |
|---|---|---|
| Little to no exercise | 0.8 - 1.0 | Around the basic requirement for a typical adult |
| Light exercise, 2-3x/week | 1.0 - 1.2 | The basic amount with some margin |
| Active exercise, 4+ times/week | 1.2 - 1.6 | In line with international guidance for people who train |
| Strength training / building muscle | 1.6 - 2.2 | The span in which benefits are seen in muscle-building studies |
The last column explains which kind of guidance each range resembles. The four ranges themselves are a simplified reference built on the published figures below, not a prescription for any individual.
Daily protein by body weight
The table multiplies each weight by the g/kg ranges above, rounded to whole grams, and is computed when the page is built. Values are grams per day.
| Body weight | Little to no exercise | Light exercise, 2-3x/week | Active exercise, 4+ times/week | Strength training / building muscle |
|---|---|---|---|---|
| 45 kg | 36-45 g | 45-54 g | 54-72 g | 72-99 g |
| 50 kg | 40-50 g | 50-60 g | 60-80 g | 80-110 g |
| 55 kg | 44-55 g | 55-66 g | 66-88 g | 88-121 g |
| 60 kg | 48-60 g | 60-72 g | 72-96 g | 96-132 g |
| 65 kg | 52-65 g | 65-78 g | 78-104 g | 104-143 g |
| 70 kg | 56-70 g | 70-84 g | 84-112 g | 112-154 g |
| 75 kg | 60-75 g | 75-90 g | 90-120 g | 120-165 g |
| 80 kg | 64-80 g | 80-96 g | 96-128 g | 128-176 g |
| 90 kg | 72-90 g | 90-108 g | 108-144 g | 144-198 g |
| 100 kg | 80-100 g | 100-120 g | 120-160 g | 160-220 g |
If you think in pounds, divide by 2.2046 to get kilograms: 154 lb is about 69.9 kg.
What do published guidelines say?
- WHO/FAO/UNU expert report (2007): gave a safe intake of about 0.83 g/kg/day for healthy adults. This is close to the level that prevents deficiency, and it does not mean the amount is optimal for people who train heavily or for older adults.
- International Society of Sports Nutrition position stand (2017): suggests roughly 1.4 to 2.0 g/kg/day for people doing resistance or endurance training.
- Older adults (for example the PROT-AGE study group): there is expert opinion that healthy older adults should aim for at least 1.0 to 1.2 g/kg/day, and more may be needed with illness or sarcopenia. Individual advice for older people should come from a doctor or dietitian.
- National reference intakes: many countries publish their own recommended intakes, which vary by age and sex and may also give a share of total energy. Check your national guideline for the exact figures, because they are not reproduced here.
The numbers look different because the goals differ. General-population standards aim to prevent deficiency in most healthy people, while sports nutrition guidance aims to optimize adaptation and recovery. That is why this tool moves the range upward as the activity level rises.
Worked examples
Example 1: 65 kg, little to no exercise. 65 Γ 0.8 = 52 g and 65 Γ 1.0 = 65 g, so 52 to 65 g a day. Split across 3 meals that is about 17 to 22 g per meal. The calories from protein are 52 Γ 4 = 208 kcal up to 65 Γ 4 = 260 kcal.
Example 2: 70 kg, strength training and building muscle. 70 Γ 1.6 = 112 g and 70 Γ 2.2 = 154 g, so 112 to 154 g a day. Over 4 meals that is 28 to 38.5 g each, and 448 to 616 kcal. The range is wide, so it is practical to start near the bottom (1.6 g/kg) and adjust according to appetite, digestion and cost.
Example 3: 60 kg, light exercise. 60 Γ 1.0 = 60 g and 60 Γ 1.2 = 72 g, so 60 to 72 g. Two eggs (about 12 g), 150 g of tofu (10 to 12 g) and 100 g of chicken breast (about 22 g) already cover a large share of it, and the rest comes easily from milk, grains and vegetables.
How much per meal, and how to spread it
With the same daily total, spreading protein over several meals is thought to be better for muscle protein synthesis than eating it all at once, and for people who train a figure of roughly 20 to 40 g per meal is often suggested. That is a general rule that varies with body size and age, not a fixed requirement. The "per meal" figure in the tool is simply the daily total divided by the number of meals you enter. The table below shows typical protein in common foods. These are approximations that depend on the product and how it is cooked, so a nutrition label should take priority.
| Food (serving) | Protein (approx.) |
|---|---|
| 1 egg (about 50 g) | about 6 g |
| Chicken breast, 100 g (raw) | about 22-23 g |
| Tofu, 150 g | about 10-12 g |
| Milk, 200 mL | about 6-7 g |
| Greek yogurt, 100 g | about 8-10 g (varies a lot by brand) |
| Cooked rice, 210 g (one bowl) | about 5 g |
Common mistakes and myths
- Using total weight when body fat is high: multiplying current weight by a high g/kg rate can overshoot. For people with obesity, dietitians sometimes work from a target or reference weight instead, which is best decided with a professional. The BMI calculator shows a healthy weight range for your height.
- "The more the better": studies suggest the extra benefit levels off above a certain intake, and the top of this tool's scale (2.2 g/kg) is best treated as a ceiling near that point.
- Confusing food weight with protein grams: 100 g of chicken breast does not contain 100 g of protein. Only part of the weight is protein, as the table above shows.
- Ignoring total calories: raising protein while eating too little makes building muscle hard, and eating too much adds fat as well. Use the calorie calculator and the BMR and TDEE calculator to set the total first.
- Believing supplements are required: if food can cover the target, a powder is a convenience, not a necessity.
When not to use these numbers as they are
- Chronic kidney disease or reduced kidney function: protein may need to be limited, so follow your own doctor's instructions.
- Liver disease, inherited metabolic disorders such as phenylketonuria, or gout treatment: individual diet prescriptions come first.
- Pregnancy or breastfeeding: needs are different from the general adult range, so ask your care team.
- Children and teenagers: growth stages have their own reference values.
- After surgery, with pressure injuries, serious illness or age-related muscle loss: needs can differ greatly from those of a healthy adult.
What to do with the result
- Start at the low end of your range and record what you eat for about two weeks to see your actual intake.
- If you fall short, add one protein food to each meal, such as eggs, tofu, fish, lean meat, dairy or legumes.
- When cutting calories, keeping protein steady helps limit muscle loss. The body fat calculator helps you follow the trend.
- More exercise also raises your energy use, which the exercise calorie calculator estimates.
- Protein-rich diets also depend on fluid intake. The water intake calculator gives a starting point.
Please note
These results are reference information for generally healthy adults and are not medical advice, a diagnosis or a nutrition prescription. If you have a medical condition or take medication, talk with a doctor or registered dietitian. Your values are calculated in the browser and are not sent to a server.
Frequently Asked Questions
Is too much protein a problem?
In adults with healthy kidneys, many studies find intakes in the usual high-protein range (around 2 g/kg) to be safe in the short and medium term. Evidence on long-term effects is more limited, and anyone with kidney disease must agree intake with a health professional. Not drinking enough fluid on a high-protein diet can also cause discomfort.
Do I need more protein when dieting?
When calories are cut, muscle is easily lost too, so people are usually advised to keep protein at its usual level or raise it slightly. In this tool you can get a rough idea by stepping up one activity level, but personal plans are best made with a dietitian.
Is plant protein enough?
A varied mix of legumes, tofu, grains and nuts can supply all the essential amino acids. Plant proteins can be slightly less digestible and lower in some amino acids such as lysine, so some experts suggest people eating entirely plant-based aim for the upper end of their range.
Must I eat protein within 30 minutes of training?
The idea of a 30-minute "anabolic window" is widely regarded as exaggerated. The daily total and how it is spread across meals matter more, and a protein-containing meal within a few hours before or after training is generally considered enough.
Do older adults need a different amount?
Because muscle responds less to protein with age, some international expert opinion recommends more than the basic adult amount, around 1.0 to 1.2 g/kg or higher. For your own figure and your country's guideline, check with a clinician or dietitian.