Protein calculator —
your daily target by goal & activity.

Field guide

How much protein do you actually need?

Why protein matters more than most nutrients

Protein is the only macronutrient that can both build new tissue and prevent the breakdown of existing tissue. It supplies the amino acids your body needs to synthesise skeletal muscle, enzymes, hormones, antibodies, and structural proteins like collagen. Unlike carbohydrates and fat, there is no meaningful storage depot for protein. Your body is constantly turning it over, breaking proteins down and rebuilding them from dietary amino acids.

This constant flux, called protein turnover: means your daily protein intake must stay above a certain threshold or your body cannibalises lean tissue (muscle, organ protein) to meet its amino acid needs. During a caloric deficit, this process accelerates, which is why high-protein diets are critical for fat loss as much as for muscle building.

The US RDA: a floor, not a target

The US Recommended Dietary Allowance (RDA) for protein is 0.8 g per kilogram of body weight per day. This is frequently cited as the recommended intake, but it is widely misunderstood. The RDA is calculated to prevent deficiency in the average sedentary adult. It is the estimated minimum, not an optimum.

For anyone who exercises regularly, is over 50, wants to build muscle, or is dieting, the RDA is inadequate. Multiple systematic reviews and meta-analyses consistently show that protein intakes of 1.4–2.2 g/kg produce better outcomes for health, body composition, and performance than the RDA in all active populations.

Goal-specific protein targets

Building muscle: 1.6–2.2 g/kg

The landmark 2018 meta-analysis by Morton et al. (British Journal of Sports Medicine) pooled data from 49 randomised controlled trials and 1,800 participants. It found that protein intakes beyond 1.62 g/kg/day produced no additional muscle hypertrophy. Most practitioners recommend 1.6–2.0 g/kg as the practical sweet spot, with the upper bound at 2.2 g/kg providing a buffer for measurement error and higher-volume training phases.

Fat loss: 1.6–2.7 g/kg

During a caloric deficit, higher protein intakes are even more important than during maintenance or surplus. Protein preserves lean mass (muscle) as your body loses fat, and it has the highest thermic effect of all macronutrients (~25–30% of its calories are burned in digestion, versus 5–10% for carbs and fat). Research by Helms, Phillips, and others suggests 1.8–2.4 g/kg for natural athletes, with some studies on very lean individuals finding benefits up to 3.1 g/kg of lean body mass.

Maintenance: 0.8–2.0 g/kg

The ISSN's 2017 position statement recommends 1.4–2.0 g/kg for generally active adults as the optimal range. The RDA of 0.8 g/kg is the safe minimum for sedentary individuals, but even sedentary older adults benefit from higher intakes (1.0–1.2 g/kg) to counteract age-related muscle loss (sarcopenia). For the general exercising population, 1.4–1.6 g/kg is a pragmatic and evidence-backed target.

Endurance sports: 1.2–1.8 g/kg

The joint position statement from ACSM, AND, and Dietitians of Canada recommends 1.2–1.6 g/kg for endurance athletes. Higher intakes (up to 1.8 g/kg) are appropriate during heavy training blocks, for masters athletes, and for those who perform combined endurance and resistance training. Endurance athletes often under-estimate protein needs because protein isn't a primary fuel for aerobic performance, but muscle repair, immune function, and adaptation all depend on it.

Protein distribution — the per-meal question

Total daily protein matters most, but distribution across meals also plays a role. Research on muscle protein synthesis (MPS) consistently shows that20–40 g of high-quality protein per meal is near the ceiling for maximal acute MPS in most people. Consuming 60 g in one sitting does not double the muscle-building response compared to 30 g.

This doesn't mean you can't eat one large protein meal — the difference between 3 and 6 meals at matched daily protein is modest in practice. But spreading protein across 3–5 meals is a sensible strategy for maximising the anabolic signal throughout the day and avoiding digestive overload.

Protein quality and leucine threshold

Not all protein is equal. Leucine, a branched-chain amino acid, is the primary trigger for MPS. Complete protein sources — animal products, soy, pea/rice blends — contain all essential amino acids including sufficient leucine (~2–3 g per serving) to fully stimulate MPS. Incomplete sources or lower-leucine proteins may require larger servings to achieve the same anabolic response.

The gram targets in this calculator assume you are eating predominantly complete, high-quality protein sources. If your diet is primarily plant-based, target the upper portion of your range to compensate for amino acid limitations.

Disclaimer

This calculator provides general population estimates based on peer-reviewed literature. Individual requirements vary with genetics, gut health, protein source quality, and medical conditions. This is not dietary or medical advice. Consult a registered dietitian for personalised guidance.