Protein Calculator

Free Daily Protein Intake Calculator

Protein is one of the three macronutrients your body needs every day. It plays a critical role in building and repairing muscle tissue, producing enzymes and hormones, supporting immune function, and maintaining healthy skin, hair, and nails. Whether you are trying to lose weight, build muscle, or simply maintain a healthy body composition, getting enough protein is essential.

How Much Protein Do You Need?

The amount of protein you need depends on three main factors: your body weight, how active you are, and what your fitness goals are. The traditional Recommended Dietary Allowance (RDA) set by the National Academy of Medicine is 0.8 g/kg of body weight per day (0.36 g/lb) for sedentary adults. However, the 2025–2030 Dietary Guidelines for Americans increased this recommendation to 1.2–1.6 g/kg per day, reflecting decades of research showing that higher protein intake supports muscle maintenance, metabolic health, and satiety.

The International Society of Sports Nutrition (ISSN) position stand recommends 1.4–2.0 g/kg/day for exercising individuals, and up to 2.3–3.1 g/kg/day to maximize lean mass retention during a calorie deficit. A 2022 systematic review and meta-analysis of 74 randomized controlled trials confirmed that protein intakes above the RDA significantly improve lean mass and strength outcomes in healthy adults.

Protein and Weight Loss

Higher protein intake is especially important during a calorie deficit. When you eat fewer calories than you burn, your body can break down muscle for energy. Research from NASM recommends approximately 1.6 g/kg (0.73 g/lb) per day to spare lean body mass during weight loss. People who maintain a high protein diet during a deficit retain more muscle, feel more satisfied between meals, and have better long-term success maintaining their weight loss.

Do Gender or Age Matter?

Protein recommendations expressed in grams per kilogram of body weight apply equally to men and women. Since the calculator uses your body weight as the input, the difference in absolute grams between sexes is already accounted for. A Gatorade Sports Science Institute review found no evidence that women need different g/kg ratios than men. Age is a factor for older adults (65+) — research published in the American Journal of Clinical Nutrition suggests 1.2–1.6 g/kg/day for older adults to prevent sarcopenia. If you are over 65, consider selecting a higher activity level or goal to push your target into this range.

Spreading Protein Across Meals

The ISSN position stand recommends 0.25 g/kg of high-quality protein per serving (roughly 20–40 g per meal), distributed every 3–4 hours across the day. This is more effective for muscle protein synthesis than consuming most of your protein in a single meal. This calculator shows your per-meal target based on whether you eat 3, 4, or 5 meals per day.

Plant-Based Protein

You do not need to eat animal products to meet your protein needs. Lentils, tofu, tempeh, edamame, chickpeas, quinoa, and seitan are all excellent plant-based protein sources. Combining different plant proteins throughout the day ensures you get all essential amino acids. Plant-based eaters may benefit from targeting the higher end of the recommended range to account for slightly lower digestibility of some plant proteins.

Sources

• Jäger R, et al. “International Society of Sports Nutrition Position Stand: Protein and Exercise.” JISSN, 2017.
• Nunes EA, et al. “Systematic review and meta-analysis of protein intake to support muscle mass and function in healthy adults.” J Cachexia Sarcopenia Muscle, 2022.
• Harvard T.H. Chan School of Public Health. “Dietary Guidelines for Americans 2025–2030.” 2026.
• Bauer J, et al. “Protein Requirements and Optimal Intakes in Aging.” Adv Nutr, 2018.
• Harvard Health Publishing. “How much protein do you need every day?”
• Gatorade Sports Science Institute. “Muscle Protein Metabolism and Protein Requirements for Female Athletes.”

Frequently Asked Questions