Protein Intake Calculator
This calculator provides multiple evidence-informed ways to estimate daily protein needs: weight-based (grams per kilogram), DRI-based, calorie- and goal-based, and a clinical pathway adjusted for kidney function. It is designed for transparency and reproducibility.
Results are estimates for planning and discussion. They are not a substitute for individualized medical or dietetic advice, especially for clinical conditions. Refer to the citations for primary sources and measurement standards.
Estimate protein as grams per kilogram of body weight adjusted for activity level and goal.
Inputs
Results
Daily protein (grams)
0
Protein per kg
1.2
| Output | Value | Unit |
|---|---|---|
| Daily protein (grams) | 0 | g |
| Protein per kg | 1.2 | g/kg |
Visualization
Methodology
Weight-based method multiplies body mass (kg) by a recommended rate (g/kg) adjusted for activity level and training goals. Rates reflect ranges commonly used in nutrition science and sports nutrition literature.
DRI-based method follows recommended population intakes (RDA) expressed per kg of body weight and adjusts for life stages like pregnancy and lactation.
Calorie-based method converts a chosen percent of energy to grams of protein using 4 kcal per gram. This is useful when macronutrient distribution is driven by overall energy targets.
Clinical kidney-adjusted method reduces protein targets according to estimated glomerular filtration rate (eGFR). This pathway is informational and should be applied only under clinical supervision.
Key takeaways
Select the method that best matches your use case: population guidance (DRI), personal performance goals (weight-based or activity/goal), or clinical considerations (kidney-adjusted).
Consult qualified health professionals for personalized recommendations. Measurement and reporting should follow recognized standards for quality and uncertainty.
Further resources
External guidance
Expert Q&A
Is this calculator appropriate for people with medical conditions?
This tool provides informational estimates. People with chronic illnesses, renal disease, liver disease, or other medical conditions should consult a healthcare professional before changing protein intake.
Why are there different methods and different results?
Protein needs vary by age, life stage, activity, clinical condition, and planning approach (population RDA vs performance-oriented targets). Methods reflect different use cases; choose the method aligned with your goal.
How precise are the numbers?
Estimates are rounded and depend on input accuracy. Measurement and reporting follow principles from standards organizations, but biological variability means results are approximate. See accuracy caveats in citations.
Sources & citations
- National Academies — Dietary Reference Intakes — https://www.nal.usda.gov/human-nutrition-and-food-safety/dri-calculator
- NIST guidance on measurement and uncertainty — https://www.nist.gov/
- ISO standards for measurement and reporting (overview) — https://www.iso.org/standards.html
- IEEE guidance on measurement systems and data quality — https://www.ieee.org/
- OSHA: workplace nutrition and safety resources — https://www.osha.gov/