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.

Updated Nov 22, 2025QA PASS — golden 25 / edge 120Run golden-edge-2026-01-23

Governance

Record 1adde34531c4 • Reviewed by Fidamen Standards Committee

Calculation method

Estimate protein as grams per kilogram of body weight adjusted for activity level and goal.

Inputs

Weight (kg)

Min 0

Weight (lb)

Min 0

Age (years)

Min 0 · Max 120

SexActivity levelPrimary goalPregnant?Lactating?Daily energy intake (kcal)

Min 0

Estimated GFR (mL/min/1.73 m²)

Min 0 · Max 200

Results

Updates as you type

Daily protein (grams)

Protein per kg

1.2

Output	Value	Unit
Daily protein (grams)	0	g
Protein per kg	1.2	g/kg

Primary result0

Visualization

Points

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.

F.A.Q.

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/
CDC — Body Mass Index (BMI) Categories — https://www.cdc.gov/bmi/adult-calculator/bmi-categories.html
NIH — National Institutes of Health Metabolic Research — https://www.nih.gov/
ACSM — American College of Sports Medicine Guidelines — https://www.acsm.org/
PubMed — Mifflin-St Jeor Equation (PMID: 2305711) — https://pubmed.ncbi.nlm.nih.gov/2305711/

Further resources

Related tools

External guidance

Versioning & Change Control

Audit record (versions, QA runs, reviewer sign-off, and evidence).

Record ID: 1adde34531c4

What changed (latest)

v1.0.0 • 2025-11-22 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Public QA status

PASS — golden 25 + edge 120

Last run: 2026-01-23 • Run: golden-edge-2026-01-23

Engine

v1.0.0

Data

Baseline (no external datasets)

Content

v1.0.0

Governance

Last updated: Nov 22, 2025

Reviewed by: Fidamen Standards Committee (Review board)

Credentials: Internal QA

Risk level: low

Reviewer profile (entity)

Fidamen Standards Committee

Review board

Internal QA

Entity ID: https://fidamen.com/reviewers/fidamen-standards-committee#person

Semantic versioning

MAJOR: Calculation outputs can change for the same inputs (formula, rounding policy, assumptions).
MINOR: New features or fields that do not change existing outputs for the same inputs.
PATCH: Bug fixes, copy edits, or accessibility changes that do not change intended outputs except for previously incorrect cases.

Review protocol

Verify formulas and unit definitions against primary standards or datasets.
Run golden-case regression suite and edge-case suite.
Record reviewer sign-off with credentials and scope.
Document assumptions, limitations, and jurisdiction applicability.

Assumptions & limitations

Uses exact unit definitions from the Fidamen conversion library.
Internal calculations use double precision; display rounding follows the unit's configured decimal places.
Not a substitute for calibrated instruments in regulated contexts.
Jurisdiction-specific rules may require official guidance.

Change log

v1.0.0 • 2025-11-22 • MINOR

Initial publication and governance baseline.

Why: Published with reviewed formulas, unit definitions, and UX controls.

Areas: engine, content, ui • Reviewer: Fidamen Standards Committee • Entry ID: fe4a96dc78de