Quick answer: Multiply your weight in kg by 0.8 to 2.2 g per kg depending on your goal: 0.8 is the RDA floor for sedentary adults, 1.2-1.6 fits active people, and 1.6-2.2 covers muscle building. A 70 kg sedentary adult needs about 56-70 g of protein per day.
Last reviewed: November 2026
Key facts
- Daily protein = weight (kg) x g/kg target for your goal.
- 0.8 g/kg is the official floor (RDA), not an optimal target.
- Active lifters do best at 1.6-2.2 g/kg; older adults at 1.0-1.6 g/kg.
- Spread intake across the day: about 20-40 g per meal supports muscle building best.
A protein calculator turns your body weight and goal into a daily protein target. Pick your activity and goal, enter your weight, and it gives you a personalized gram range to aim for each day. It also breaks targets into pre- and post-workout windows and compares animal versus plant protein completeness.
The RDA of 0.8 g/kg keeps a sedentary adult from becoming deficient, but it was never built for lifters, dieters, or older adults. Strength athletes need roughly double that to repair and grow muscle, and people over 40-50 need more than the floor to fight age-related muscle loss. This protein calculator maps your goal to the research-backed range so you get a target, not a minimum.
How to use the protein calculator
- Enter your body weight in kg or lb.
- Pick your goal: sedentary, lightly active, moderately active, very active, building muscle, or losing weight.
- Click Calculate to get your daily protein range in grams.
- Divide the range by your meals per day to set per-meal targets.
Protein calculator formula
The g/kg factor is 0.8-1.0 for sedentary adults, 1.0-1.2 lightly active, 1.2-1.6 moderately active, 1.4-1.8 very active, 1.6-2.0 for building muscle, and 1.6-2.2 when losing weight while preserving muscle. If you entered pounds, divide by 2.20462 first: 180 lb = 81.6 kg.
Worked examples
Sedentary adult: 70 kg
At 0.8-1.0 g/kg: 70 x 0.8 = 56 g to 70 x 1.0 = 70 g per day. Over 3 meals, that is about 19-23 g per meal.
Building muscle: 180 lb (81.6 kg)
At 1.6-2.0 g/kg: 81.6 x 1.6 = 131 g to 81.6 x 2.0 = 163 g per day. Over 4 meals, that is about 33-41 g per meal.
Protein targets by goal
| Goal | g per kg of body weight | Example (80 kg) |
|---|---|---|
| Sedentary | 0.8 - 1.0 | 64 - 80 g |
| Lightly active | 1.0 - 1.2 | 80 - 96 g |
| Moderately active | 1.2 - 1.6 | 96 - 128 g |
| Very active | 1.4 - 1.8 | 112 - 144 g |
| Building muscle | 1.6 - 2.0 | 128 - 160 g |
| Losing weight | 1.6 - 2.2 | 128 - 176 g |
Tips for hitting your protein target
A target only works if you can reach it every day. Start by anchoring each meal with a palm-sized portion of a protein-rich food: eggs or Greek yogurt at breakfast, chicken, fish, or tofu at lunch and dinner. That pattern usually lands you at 25-35 g per meal without any weighing. If your protein calculator result is high, say 150 g or more, a protein shake or two per day fills the gap without adding much bulk to your meals. Front-load protein earlier in the day instead of saving it all for dinner, since spreading intake across 3-5 meals supports muscle building better than one huge evening meal. Finally, recalculate whenever your weight or goal changes: a cutting phase and a bulking phase at the same body weight can differ by 30-40 g a day.
Frequently asked questions
How much protein do I need per day?
Multiply your weight in kg by 0.8-2.2 g/kg for your goal: 0.8 for sedentary adults, 1.2-1.6 for active people, and 1.6-2.2 for building muscle or dieting. A 70 kg sedentary adult needs about 56-70 g a day.
Is 0.8 g/kg enough protein?
It is the official RDA floor: the minimum to avoid deficiency in a sedentary adult, not an optimal target. Active people, dieters, and adults over 40-50 generally do better above 1.0 g/kg.
Can you eat too much protein?
For healthy people, intakes up to about 2.2 g/kg show no harm in studies. Above 2 g/kg daily counts as excessive for most purposes, and people with kidney disease or low calcium or fluid intake should stay lower and talk to a clinician.
Does protein timing matter?
The daily total matters most, but spreading protein across 3-5 meals of 20-40 g each supports muscle protein synthesis better than loading it all into one dinner. Protein right after training helps recovery.
What are the best protein sources?
Lean meats, fish, eggs, dairy, soy, beans, lentils, nuts, and seeds all count. Whole foods first: supplements are a convenience, not a requirement. If most of your protein is plant-based, aim toward the upper end of your range.
Do older adults need more protein?
Yes. After 40-50, age-related muscle loss (sarcopenia) sets in, and needs rise to about 1.0-1.6 g/kg: 75-120 g a day for a 75 kg adult. Protein plus resistance training is the best defense.
Do I need protein powder to hit my target?
No. This protein calculator gives you a gram target you can reach with whole foods alone: lean meats, fish, eggs, dairy, soy, beans, and lentils. Protein powder is a convenience for busy days or very high targets. Two shakes a day can cover 40-50 g, but real meals first is the healthier default.
How much protein is in one egg?
One large egg has about 6 g of protein: roughly 3.6 g in the white and 2.7 g in the yolk. Two eggs give you about 12 g, which is around a fifth of the daily target for a 70 kg sedentary adult (56-70 g).
Should I use my actual weight if my BMI is over 30?
No, use an adjusted body weight, because fat tissue needs very little protein and your actual weight would inflate the target. Adjusted weight = ideal weight + 0.4 x (actual weight - ideal weight). For a 100 kg man who is 170 cm tall, ideal weight is about 66 kg, so adjusted weight is about 80 kg: at 1.2 g/kg that gives 96 g a day instead of 120 g.
Related calculators
- Calorie Calculator: work out your daily calorie needs to pair with your protein target.
- Macro Calculator: split your calories into protein, carbs and fat.
- TDEE Calculator: find your total daily energy expenditure first, then set protein within it.
Sources
- National Academies: Dietary Reference Intakes for macronutrients, the official source of the 0.8 g/kg protein RDA
- Dietary Guidelines for Americans: federal nutrition guidance from USDA and HHS
Key takeaways
- Bookmark this protein calculator for quick recalculations whenever your inputs change.
- Daily protein = weight (kg) x 0.8-2.2 g/kg for your goal.
- 0.8 g/kg is the deficiency floor; lifters and dieters need 1.6-2.2.
- Spread intake over 3-5 meals of 20-40 g each.
- Older adults should target 1.0-1.6 g/kg to protect muscle.
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