Protein Calculator

How Much Protein Do I Need?

Protein is the most important macronutrient for body composition, muscle repair, immune function, and satiety. The optimal daily intake depends on your body weight and fitness goal.

Protein Intake by Goal

Goal	Protein per kg	Example (70 kg person)
Maintain general health	0.8–1.0 g/kg	56–70 g/day
Weight loss (preserve muscle)	1.2–1.5 g/kg	84–105 g/day
Build muscle (hypertrophy)	1.6–2.2 g/kg	112–154 g/day
Athletic performance	1.8–2.7 g/kg	126–189 g/day

WHO/NIH Recommended Dietary Allowance (RDA)

The minimum protein RDA set by the WHO and NIH is 0.8g per kg of body weight per day. This is the minimum to prevent deficiency in sedentary adults — it is not an optimal target for active individuals.

RDA by Age Group

Age Group	Daily Protein (g)
1–3 years	13 g
4–8 years	19 g
9–13 years	34 g
14–18 years (Female)	46 g
14–18 years (Male)	52 g
19+ (Female)	46 g
19+ (Male)	56 g

Protein for Muscle Building

Current research (meta-analyses of resistance training studies) consistently shows that 1.6g/kg/day is the point beyond which additional protein provides diminishing returns for muscle synthesis. However, higher intakes (up to 2.2g/kg) may help preserve muscle during a calorie deficit.

The "1 gram per pound" rule (approximately 2.2g/kg) is popular in fitness communities and falls at the upper end of the evidence-based range. It is safe and effective, though not strictly necessary.

Protein Timing

Research suggests muscles can effectively utilise 20–40g of protein per meal for muscle protein synthesis. Distributing your daily protein across 4–5 meals maximises muscle-building signal compared to consuming it in one or two large meals.

Best Protein Sources

Animal sources (complete proteins):

• Chicken breast (31g per 100g)
• Greek yoghurt (10g per 100g)
• Eggs (13g per 100g)
• Salmon (25g per 100g)
• Lean beef (26g per 100g)

Plant sources (often incomplete, combine for full amino acid profile):

• Lentils (9g per 100g cooked)
• Tofu (8g per 100g)
• Chickpeas (9g per 100g cooked)
• Edamame (11g per 100g)

Can You Eat Too Much Protein?

For healthy adults with normal kidney function, intakes up to 3.5g/kg/day appear safe long-term. However, extremely high protein intakes offer no additional benefit and crowd out carbohydrates and fats that provide other important nutrients.

Individuals with pre-existing kidney disease should consult their doctor before high-protein diets.

The Science of Muscle Protein Synthesis

Muscle protein synthesis (MPS) is the cellular process by which your body repairs and builds muscle fibres. It is triggered primarily by:

1. Mechanical loading (resistance training)

2. The presence of essential amino acids — particularly leucine

Leucine acts as a molecular "switch" that activates the mTOR signalling pathway, which initiates the protein synthesis cascade. Research suggests a minimum of 2–3 g of leucine per meal is required to maximally stimulate MPS. This corresponds to approximately 25–35 g of high-quality animal protein or 35–50 g of most plant proteins.

MPS is elevated for 24–48 hours after a resistance training session. Providing sufficient dietary protein during this window maximises the anabolic response to training.

Protein Quality: Complete vs. Incomplete

Not all protein sources have equal amino acid profiles. Complete proteins contain all nine essential amino acids (EAAs) in adequate quantities. These include:

• All animal proteins (meat, poultry, fish, dairy, eggs)
• Soy protein
• Quinoa
• Buckwheat

Incomplete proteins lack or are low in one or more EAAs. Most plant proteins fall here. However, combining complementary plant proteins (e.g., rice + beans) throughout the day provides all EAAs without requiring simultaneous consumption.

Protein for Weight Loss: Why It Matters More Than Calories Alone

High-protein diets are particularly effective for fat loss because:

1. Satiety: Protein is the most satiating macronutrient. A high-protein meal reduces appetite hormones (ghrelin) and increases satiety hormones (GLP-1, PYY) more than equivalent calories from carbohydrates or fat. This naturally reduces overall calorie intake without requiring willpower.

2. Thermic Effect: 20–30% of protein calories are used in digestion. A diet providing 150 g of protein per day "burns" an additional 80–120 kcal just through this metabolic cost.

3. Muscle Preservation: During a calorie deficit, the body can break down muscle protein for energy (gluconeogenesis). Higher protein intake — particularly above 1.6 g/kg — significantly reduces muscle loss during weight loss, preserving the lean mass that keeps your metabolism elevated.

Protein for Specific Populations

Older adults (65+): Age-related muscle loss (sarcopenia) begins accelerating in the 6th decade. Research suggests older adults require 1.2–1.6 g/kg just to maintain muscle mass — significantly above the WHO RDA of 0.8 g/kg. The PROT-AGE and ESPEN guidelines now recommend 1.0–1.2 g/kg as a minimum for older adults, with 1.2–1.6 g/kg for those who are active.

Pregnant women: Protein needs increase to support foetal growth. The UK DRV is 51 g/day during pregnancy (an increase of ~6 g above the standard 45 g/day for adult women). In practice, many researchers recommend 1.0–1.1 g/kg throughout pregnancy.

Endurance athletes: Contrary to the muscle-centric view of protein, endurance athletes also have elevated needs — approximately 1.2–1.6 g/kg — because amino acids are used as fuel during prolonged aerobic exercise, and muscle protein breakdown is significant during ultra-endurance events.

How to Hit Your Protein Target: Practical Strategies

Many people struggle to consume 130–170 g of protein per day. These strategies make it manageable:

1. Prioritise protein at every meal — build meals around a protein anchor (chicken, fish, eggs, tofu) before adding sides

2. Use Greek yoghurt — 150 g of full-fat Greek yoghurt provides 15–18 g of protein with minimal preparation

3. Breakfast protein — the most-skipped opportunity. 3 scrambled eggs + 150 g Greek yoghurt = 30+ g by 9 AM

4. Protein shakes as a supplement, not a crutch — whey provides 25 g per serving in under 60 seconds. Useful for bridging gaps, but whole food protein sources provide more micronutrients

5. Cottage cheese as a bedtime snack — high in casein protein, which digests slowly over 6–8 hours, supporting overnight muscle repair

Related Resources

Related Calculators

• Macro Calculator — Find your ideal protein, carb, and fat split.
• Calorie Calculator — Balance your protein intake with daily calories.

External Authority Resources

• International Society of Sports Nutrition Position Stand — Review of protein intake and exercise.
• National Institutes of Health Dietary Reference Intakes — Standard government protein recommendations.

Sources

• WHO. Protein and Amino Acid Requirements in Human Nutrition. 2007.
• Morton RW et al. A systematic review, meta-analysis and meta-regression of the effect of protein supplementation on resistance training–induced gains in muscle mass and strength. Br J Sports Med. 2018;52(6):376-384.
• Phillips SM. Dietary protein requirements and adaptive advantages in athletes. Br J Nutr. 2012.
• Stokes T et al. Recent Perspectives Regarding the Role of Dietary Protein for the Promotion of Muscle Hypertrophy with Resistance Exercise Training. Nutrients. 2018;10(2):180.