Calculate daily protein needs by goal
A protein calculator estimates how many grams of protein you need per day based on your body weight, activity level, and goal — such as maintaining muscle, building muscle, or losing fat while preserving lean mass. Protein needs vary more by goal and activity than most other macronutrients.
The calculator multiplies body weight by a grams-per-unit rate that rises with the goal, from 0.8 g per kg for a sedentary adult up to 2.2 g per kg for fat loss with muscle preservation (0.36 to 1.0 g per lb). The result is rounded to whole grams and split evenly across the number of meals you choose. The range shown is the daily figure minus and plus 15 percent, which reflects day-to-day variation rather than medical limits.
Daily Protein (g) = Body Weight (kg) × Protein Factor (0.8–2.2 g/kg depending on activity and goal)
| Calculation | Expression | Result |
|---|---|---|
| 180 lb person, strength training | 180 lb × 0.73 g/lb | 131 g per day |
| Split across 4 meals | 131 g ÷ 4 | 33 g per meal |
| Range shown | 131 g × 0.85 and × 1.15 | 111 g to 151 g |
| 80 kg person, strength training | 80 kg × 1.6 g/kg | 128 g per day |
It depends on your goal and activity level: roughly 0.8 g/kg for general health, 1.2–1.6 g/kg for active adults, and 1.6–2.2 g/kg for muscle building or fat loss while preserving muscle. Use your body weight in kilograms and multiply by the factor for your goal.
For most healthy adults, protein intake up to around 2.2 g/kg per day is considered safe. People with pre-existing kidney conditions should consult a doctor before significantly increasing protein intake.
Most recommendations use your current body weight. If you're significantly overweight, some calculators use lean body mass or an adjusted weight instead, since protein needs scale more closely with lean tissue than fat mass.
Yes — protein is more satiating than carbs or fat, and higher protein intake during a calorie deficit helps preserve muscle mass, so more of the weight lost comes from fat rather than lean tissue.
All dietary protein counts, from meat, fish, eggs, and dairy to plant sources like beans, lentils, tofu, and protein powder. The calculator gives you a gram target — how you reach it is up to your food choices.
No. It is the daily figure minus and plus 15 percent, for example 111 g to 151 g around 131 g, to show that intake varies from day to day. It is not a safe-limit calculation, and anyone with a kidney condition or other medical issue should ask a clinician before changing protein intake.