How to use the protein intake calculator
- Enter your body weight in the first field.
- Select your weight unit: kilograms or pounds.
- Choose your fitness goal from the dropdown menu.
- Read your recommended daily protein grams in the result panel below.
How the protein calculation works
This protein intake calculator converts your weight to kilograms if needed, then multiplies it by a factor based on your selected goal. The exact conversion used for pounds is 1 lb = 0.45359237 kg.
The multipliers applied per kilogram of body weight are:
- Sedentary: 0.8 g/kg, matching the Recommended Dietary Allowance for general health.
- Active / maintain: 1.6 g/kg, suitable for regular exercise without a specific body composition goal.
- Build muscle: 2.0 g/kg, aligned with research showing optimal muscle protein synthesis at this level.
- Lose fat: 2.4 g/kg, higher to prevent muscle breakdown during a caloric deficit.
For example, a person weighing 180 lb who wants to lose fat first converts their weight: 180 x 0.45359237 = 81.65 kg. Then the calculator applies the fat loss multiplier: 81.65 x 2.4 = 195.95, which rounds to 196 grams of protein per day.
Daily protein reference table
The table below shows pre-calculated daily protein targets for common body weights across all four goals. Use it as a quick reference alongside the calculator above.
| Body weight | Sedentary (0.8 g/kg) | Maintain (1.6 g/kg) | Build muscle (2.0 g/kg) | Lose fat (2.4 g/kg) |
|---|---|---|---|---|
| 60 kg (132 lb) | 48 g | 96 g | 120 g | 144 g |
| 70 kg (154 lb) | 56 g | 112 g | 140 g | 168 g |
| 80 kg (176 lb) | 64 g | 128 g | 160 g | 192 g |
| 90 kg (198 lb) | 72 g | 144 g | 180 g | 216 g |
| 100 kg (220 lb) | 80 g | 160 g | 200 g | 240 g |
Why protein needs change with your goal
Your fitness goal directly determines how much protein you require. When you are sedentary, your body only needs enough amino acids to repair normal daily wear and tear, which is why the baseline recommendation sits at 0.8 grams per kilogram.
Resistance training creates micro-tears in muscle fibers. Repairing these tears requires additional amino acids, pushing the optimal range to 1.6 through 2.2 grams per kilogram. If you are actively trying to build muscle while eating at a caloric surplus, 2.0 g/kg provides a reliable target that covers most individuals without unnecessary excess.
Fat loss presents a different challenge. When you eat fewer calories than you burn, your body may break down muscle tissue for energy. Consuming more protein, around 2.4 g/kg, signals the body to preserve lean mass while mobilizing fat stores. Pairing adequate protein with proper hydration is also important; you can use a water intake calculator to ensure you are drinking enough fluids to support digestion and nutrient transport.
Common mistakes when tracking protein
Many people confuse total food weight with protein content. A 200-gram chicken breast does not contain 200 grams of protein; it contains roughly 60 grams, because meat is mostly water. Always check nutritional labels or use a food database to find the actual protein per serving.
Another frequent error is using total body weight when carrying significant excess body fat. Because fat tissue requires very little protein to maintain, using total weight can overestimate your needs. In such cases, some practitioners recommend calculating protein based on lean body mass or a target body weight instead. While this tool uses total weight for simplicity, be aware that the resulting number may be slightly high if your body fat percentage is well above average.
Finally, spreading protein evenly across meals improves utilization. Eating 150 grams in a single sitting is less effective for muscle protein synthesis than dividing it into four meals of roughly 35 to 40 grams each.
Practical sources to hit your daily target
Knowing your daily protein grams is only useful if you can translate it into actual meals. Here are approximate protein values for common whole foods:
- Chicken breast (cooked, 100 g): 31 g
- Eggs (one large): 6 g
- Greek yogurt (plain, 170 g): 15 g
- Canned tuna (drained, 100 g): 25 g
- Tofu (firm, 100 g): 8 g
- Lentils (cooked, 100 g): 9 g
- Whey protein powder (one scoop): 24 g
If your protein intake calculator result is 140 grams, you might achieve that with two eggs at breakfast (12 g), a chicken breast salad at lunch (35 g), Greek yogurt as a snack (15 g), a portion of tuna with dinner (50 g), and a protein shake before bed (24 g). Adjust portions based on the exact brands and cuts you buy.
An estimate, not medical advice
The protein intake calculator uses a standard published formula, and formulas describe averages, not you. Age, body composition, medical conditions, medication, pregnancy and training history can all move the real number. Use the result as a starting point for planning, and speak to a doctor, dietitian or qualified coach before making health, diet or training decisions, especially if you have a medical condition.
Worked examples
Each result below was produced by the same code the tool runs, so you can check your own numbers against them.
| Example | Input | Result |
|---|---|---|
| 75 kg, building muscle | Body weight: 75; Weight unit: kg; Fitness goal: muscle | Daily protein target: 150 g; Multiplier used: 2 g/kg; Weight in kilograms: 75 kg |
| 180 lb, fat loss | Body weight: 180; Weight unit: lb; Fitness goal: fatloss | Daily protein target: 196 g; Multiplier used: 2.4 g/kg; Weight in kilograms: 81.65 kg |
| 60 kg, sedentary | Body weight: 60; Weight unit: kg; Fitness goal: sedentary | Daily protein target: 48 g; Multiplier used: 0.8 g/kg; Weight in kilograms: 60 kg |
| 200 lb, maintain | Body weight: 200; Weight unit: lb; Fitness goal: maintain | Daily protein target: 145 g; Multiplier used: 1.6 g/kg; Weight in kilograms: 90.72 kg |
FAQ
How accurate is this protein intake calculator?
It uses widely accepted multipliers from sports nutrition research. Individual needs vary based on genetics, training intensity, and overall diet, but the result provides a solid starting point for most healthy adults.
Should I use my current weight or goal weight?
Use your current body weight. If you carry a very high amount of body fat, using your goal weight or lean body mass may give a more appropriate target, as fat tissue has low protein requirements.
Can I eat too much protein?
Healthy kidneys handle higher protein intakes well, but consistently exceeding 3.0 g/kg offers no added benefit for most people and displaces other essential nutrients like carbohydrates and fats from your diet.
Does the protein recommendation include plant-based diets?
Yes, the gram targets apply regardless of source. However, plant proteins are sometimes lower in certain essential amino acids, so vegans and vegetarians should eat a variety of sources like legumes, soy, and grains throughout the day.
Is my data saved or sent anywhere?
No. The calculations happen locally in your browser. Nothing is uploaded to any server, and no personal data is stored.
Why does the fat loss goal recommend more protein than building muscle?
During a caloric deficit, the body is more likely to break down muscle for energy. A higher protein intake helps preserve lean tissue while you lose fat.