Adult Protein Reference Calculator

Choose the reference context and enter body weight. The worksheet keeps the two contexts separate:

• Adult DRI population reference: 0.8 g/kg/day.
• Healthy exercising muscle context: 1.4–2.0 g/kg/day for most healthy exercising individuals specifically when building or maintaining muscle mass.

For pounds, the worksheet first uses the exact conversion:

$\text{weight in kg}=\text{weight in lb}\times 0.45359237$

It then applies the selected coefficient without rounding the converted weight:

$\text{adult DRI reference}=\text{weight in kg}\times 0.8$

$\text{healthy-exercising context}=\text{weight in kg}\times (1.4\text{ to }2.0)$

Only the displayed protein endpoints are rounded to whole grams. The kilograms used are shown with at most one decimal place. The upper endpoint of the exercising range is not preferred or universally needed.

These are population-reference calculations, not an assessment of individual need, suitability, or a medical or nutritional instruction. Body weight and a selected context cannot establish eligibility. This worksheet is not intended for children or adolescents, pregnancy or lactation, illness, clinically managed protein intake, prescribed diets, or individual kidney, liver, or other clinical decisions.

For the other side of the same DRI references, see the carb calculator; to place protein inside a daily split, use the macronutrient calculator; and for the energy equations that anchor nutrition planning, see the BMR calculator.

Sources

• Institute of Medicine of the National Academies, Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids, 2005 report, Chapter 10, printed page 589, DOI 10.17226/10490.
• Jäger et al., International Society of Sports Nutrition Position Stand: protein and exercise, Position statement item 2, DOI 10.1186/s12970-017-0177-8, PMID 28642676, PMCID PMC5477153.
• National Institute of Standards and Technology, NIST Handbook 44, 2025 edition, Appendix B, page B-12.