Calculator
Free Protein Calculator – Daily Protein Needs
Calculate your daily protein needs based on weight, activity level, and fitness goals. Free, instant, science-based protein calculator.
Quick answer
A 75 kg (165 lb) moderately active person needs approximately 120–150 g of protein per day. Athletes and people in a calorie deficit often benefit from 1.6–2.2 g per kg. Use the calculator below for your personalized recommendation.
What This Calculator Does
The PrimeMacros protein calculator estimates how many grams of protein you should eat each day based on your body weight, activity level, training intensity, and personal goals. Whether you are trying to build muscle, lose fat while preserving lean mass, or simply maintain a healthy body composition, protein is the most important macronutrient to get right.
Instead of relying on a single blanket recommendation, this tool adjusts the output using multipliers that reflect current sports nutrition research. The result is a practical daily target you can use for meal planning, grocery shopping, and tracking.
How Protein Needs Are Calculated
Most evidence-based guidelines express protein needs as grams per kilogram of body weight per day. The baseline recommendation from major health organizations is 0.8 g/kg, which is the minimum to prevent deficiency in sedentary adults. However, research consistently shows that higher intakes — between 1.2 and 2.2 g/kg — offer benefits for active individuals, older adults, and people in a calorie deficit.
The calculator applies a multiplier based on your selected activity level. For sedentary individuals it uses 0.8 g/kg, for lightly active people 1.2 g/kg, for regular exercisers 1.6 g/kg, and for intense training or bodybuilding 2.0–2.5 g/kg. If your BMI is above 30, the tool can optionally use an adjusted reference weight so the protein target remains practical rather than scaling with total body mass.
For example, a 75 kg person who trains regularly would see a recommendation of 75 × 1.6 = 120 g of protein per day. Someone of the same weight doing intense resistance training might aim for 75 × 2.0 = 150 g per day. These ranges align with position stands from the International Society of Sports Nutrition and systematic reviews published between 2017 and 2024.
Protein Recommendations by Activity Level
Sedentary adults generally need about 0.8 g of protein per kilogram — enough to maintain nitrogen balance but not optimized for muscle retention or performance. Light exercisers, such as people who walk regularly or do yoga a few times per week, benefit from 1.0–1.2 g/kg to support recovery and overall health.
Moderate to regular training — defined as three to five sessions per week including resistance or endurance work — calls for 1.4–1.8 g/kg. This range supports muscle protein synthesis, glycogen replenishment, and immune function. Competitive athletes and bodybuilders frequently consume 2.0–2.5 g/kg, particularly during cutting phases when preserving muscle in a calorie deficit is the priority.
Older adults (over 60) also benefit from the higher end of recommendations, around 1.2–1.6 g/kg, because age-related anabolic resistance means the body uses dietary protein less efficiently.
Tips for Meeting Your Protein Target
Distribute protein roughly evenly across meals rather than consuming most of it in a single sitting. Research suggests that 25–40 g per meal optimally stimulates muscle protein synthesis in most adults. If you eat four meals a day and need 140 g of protein, that works out to about 35 g per meal — achievable with a palm-sized portion of meat, fish, or legumes plus a dairy serving.
High-protein foods include chicken breast (31 g per 100 g), Greek yogurt (10 g per 100 g), eggs (6 g each), lentils (9 g per 100 g cooked), tofu (8 g per 100 g), and whey protein powder (roughly 25 g per scoop). Combining animal and plant sources throughout the day ensures a complete amino acid profile without requiring complicated planning.
If you struggle to reach your target through whole foods alone, a single protein shake can conveniently add 25–30 g. However, whole foods should remain the foundation of your intake because they provide micronutrients, fiber, and satiety that isolated supplements cannot fully replicate.
Protein recommendations by activity level (example: 75 kg person)
| Activity Level | Protein per kg | Daily Protein (75 kg) |
|---|---|---|
| Sedentary | 0.8 g | 60 g |
| Light Exercise | 1.2 g | 90 g |
| Regular Training | 1.6 g | 120 g |
| Intense Training | 2.0 g | 150 g |
| Bodybuilding / Cutting | 2.2–2.5 g | 165–188 g |
Frequently asked questions
Can you eat too much protein?
For healthy adults with normal kidney function, intakes up to 2.5 g/kg per day have not been shown to cause harm in controlled studies. However, extremely high intakes leave less room for carbs and fats, which also play important roles. If you have existing kidney disease, consult a physician before increasing protein significantly.
Is plant protein as effective as animal protein?
Plant proteins are generally lower in leucine and may have lower digestibility scores. However, combining different plant sources (such as legumes with grains) throughout the day provides a complete amino acid profile. Vegans may benefit from aiming at the higher end of the recommended range to compensate for lower bioavailability.
Does protein timing matter?
Total daily protein intake matters more than exact timing. That said, distributing protein across three to five meals (25–40 g each) appears to optimize muscle protein synthesis compared to consuming the same total in one or two large meals. Having protein within a few hours of training is beneficial but the so-called anabolic window is wider than previously thought.
How does age affect protein needs?
Adults over 60 experience anabolic resistance, meaning their muscles respond less efficiently to protein. Most researchers recommend 1.2–1.6 g/kg for older adults to help maintain muscle mass and function, which is higher than the 0.8 g/kg baseline for younger sedentary adults.
Should I adjust protein intake on rest days?
Muscle repair and protein synthesis continue for 24–48 hours after training, so maintaining a similar protein intake on rest days supports recovery. Some people slightly reduce total calories on rest days by lowering carbs or fats, but keeping protein steady is generally recommended.
Related resources
Methodology and trust notes
PrimeMacros uses common nutrition planning equations such as Mifflin-St Jeor for BMR/TDEE estimates, body-weight based protein ranges, and explicit health disclaimers. Results are planning estimates, not diagnosis, treatment or individualized nutrition therapy.
Calculator inputs are processed in the browser. Optional advertising is consent-based and the site requests non-personalized ads.