Protein Calculator
What Is a Protein Calculator?
A protein calculator estimates how many grams of protein you should eat daily based on your body weight and fitness goal. Protein is the macronutrient responsible for building and repairing muscle tissue, supporting immune function, producing enzymes and hormones, and keeping you satiated between meals.
The classic RDA of 0.36g per pound (0.8g/kg) is the minimum to prevent deficiency — not the optimal amount for most active people. Research consistently shows that 0.7–1.2g per pound of body weight supports better body composition outcomes for people who exercise.
This calculator uses evidence-based ranges from sports nutrition research, adjusted for your specific goal — from sedentary adults to competitive athletes.
How to Use This Protein Calculator
- Enter your body weight and select pounds or kilograms.
- Choose your primary goal from the dropdown.
- Click Calculate Protein Intake to see your daily gram target and per-meal suggestion.
- Use the per-meal guideline to distribute protein evenly across 3–5 meals for optimal muscle protein synthesis.
Protein Targets by Goal
| Goal | Grams per lb of body weight | For 160 lb person |
|---|---|---|
| Sedentary | 0.36–0.50g | 58–80g/day |
| Active / general fitness | 0.60–0.80g | 96–128g/day |
| Endurance athlete | 0.80–1.00g | 128–160g/day |
| Building muscle | 0.80–1.20g | 128–192g/day |
| Weight loss (preserving muscle) | 0.70–1.00g | 112–160g/day |
High-Protein Food Sources
| Food | Serving | Protein |
|---|---|---|
| Chicken breast | 3.5 oz (100g) | 31g |
| Greek yogurt | 1 cup (227g) | 20g |
| Canned tuna | 1 can (140g) | 33g |
| Eggs | 2 large eggs | 12g |
| Cottage cheese | ½ cup (113g) | 14g |
| Lentils (cooked) | 1 cup (198g) | 18g |
| Whey protein shake | 1 scoop | 25g |
Key Protein Timing Principles
- Distribute evenly across meals: Your body can effectively synthesize muscle protein from ~25–40g per meal. Cramming 100g into one meal wastes most of it.
- Post-workout window: Consuming protein within 2 hours of resistance training maximizes muscle protein synthesis. A pre-workout meal also works if within 2–3 hours prior.
- Complete vs. incomplete proteins: Animal proteins are "complete" (all essential amino acids). Plant proteins (except quinoa, soy, hemp) are incomplete — combine legumes with grains across the day.
- Leucine threshold: Muscle protein synthesis requires hitting the leucine threshold (~2.5–3g per meal). Most 25–30g protein servings contain enough leucine.
- Before bed: 30–40g of casein protein before sleep has been shown to increase overnight muscle protein synthesis by 22% in one study.
Frequently Asked Questions About Protein Intake
How much protein do I need to build muscle?
Most research supports 0.7–1.0g per pound of body weight (1.6–2.2g/kg). A 170 lb person needs 120–170g/day. Going higher (up to 1.2g/lb) does not hurt and may help during a calorie deficit.
Can I eat too much protein?
For healthy people with normal kidney function, high protein intakes (up to 3.5g/kg) appear safe. Excess protein is oxidized for energy, not stored as muscle. People with chronic kidney disease should consult a doctor.
How much protein can your body absorb at one time?
The body absorbs nearly all consumed protein, but muscle protein synthesis is maximized at roughly 25–40g per meal. The excess goes to energy or other uses. Spreading protein across meals is more effective than eating one massive serving.
How many grams of protein per day for a 200 lb person?
For general fitness: 120–160g/day. For building muscle: 160–240g/day. For weight loss: 140–200g/day. Use the calculator above with your exact weight for personalized targets.
Do I need protein shakes to hit my protein goal?
No — whole food sources are equally effective. Protein shakes are convenient for hitting daily targets but not required. Focus on getting most protein from whole foods and use shakes to fill gaps.
What is the RDA for protein?
The RDA is 0.36g per pound (0.8g/kg) per day. This is the minimum to prevent deficiency in sedentary adults — not the optimal amount for athletes, active people, older adults, or those trying to build or preserve muscle.
How much protein should women eat per day?
Women need the same grams-per-pound as men relative to body weight. A 130 lb active woman needs about 78–104g/day. Many women under-eat protein, which can slow muscle development and increase hunger.
Does protein intake matter for weight loss?
Yes. High-protein diets preserve lean mass during a calorie deficit, increase satiety (reducing overall calorie intake), and have a higher thermic effect — your body burns more calories digesting protein (20–35%) vs. carbs (5–15%) or fat (0–5%).