Health & Medicine · Dietetics
Protein Intake Calculator
Calculate your daily protein intake needs based on body weight, activity level, and fitness goal.
Calculator
Formula
P = daily protein requirement (g), W = body weight (kg), R = protein multiplier (g per kg) based on activity level and goal.
Source: ISSN Position Stand on Protein & Exercise (2017); Dietary Reference Intakes, Institute of Medicine.
How it works
The calculator applies a research-backed protein multiplier (g of protein per kg of body weight) based on your selected activity level and goal. Sedentary adults need as little as 0.8 g/kg — the minimum RDA — while strength athletes pursuing muscle gain may need up to 2.0 g/kg or more.
The goal modifier adds an additional 0.0–0.3 g/kg on top of the activity baseline: maintenance adds nothing, fat loss adds 0.2 g/kg (to preserve lean mass in a caloric deficit), and muscle gain adds 0.3 g/kg. The result is then divided across four meals to estimate a practical per-meal target.
Worked example
A 75 kg moderately active person (level 3) aiming for muscle gain (goal 3):
- Base multiplier (moderate activity): 1.2 g/kg
- Goal adjustment (muscle gain): +0.3 g/kg
- Total multiplier: 1.5 g/kg
- Daily protein: 75 × 1.5 = 112.5 g/day
- Per meal (4 meals): 112.5 ÷ 4 = 28.1 g/meal
- Protein calories: 112.5 × 4 = 450 kcal/day
Limitations & notes
This calculator uses population-level multipliers and does not account for individual metabolic variation, age-related muscle loss (sarcopenia), pregnancy, kidney disease, or sport-specific periodisation. People with renal impairment should consult a clinician before increasing protein intake, as high intakes may worsen kidney function. The 4-meal split is illustrative; actual meal distribution should match your schedule and training timing.
Frequently asked questions
What is the minimum recommended protein intake?
The RDA for sedentary adults is 0.8 g/kg of body weight per day, which is the minimum to prevent deficiency. Active individuals and older adults typically need more.
Can eating too much protein be harmful?
For healthy adults, high protein intakes (up to 2.2 g/kg) are generally safe and well-tolerated. Those with pre-existing kidney disease should follow medically supervised limits.
Does protein timing matter?
Research supports spreading protein evenly across 3–5 meals and consuming 20–40 g within a few hours of resistance training to maximise muscle protein synthesis. Total daily intake remains the most important factor.
How much protein do I need to lose fat without losing muscle?
During a caloric deficit, raising protein to 1.2–1.6 g/kg (or higher) helps preserve lean mass. This calculator adds 0.2 g/kg to the baseline when fat loss is selected.
How do I convert my weight from pounds to kilograms?
Divide your weight in pounds by 2.205 to get kilograms. For example, 154 lb ÷ 2.205 = 70 kg.
Last updated: 2025-01-15 · Formula verified against primary sources.