Protein Requirements Calculator

Protein Requirements Calculator for Nutrition. The output states the amount implied by the inputs. It is not evidence that the selected factor is appropriate for renal disease, burns, critical illness or a particular body-composition goal.

For shared guidance on choosing a tool and documenting results, read the clinical calculator workflow.

How this calculator works

Daily protein amount equals assessment weight multiplied by the entered factor. NICE CG32 supplies adult nutrition-support context; this calculator does not automatically assign a disease-specific factor.

When to use this calculator

Audit the arithmetic of a dietitian or clinician-selected plan. Identify whether the source protocol uses actual, adjusted or another assessment weight, and include protein already supplied by feeds or supplements.

Inputs used

  • Selected adult assessment weight in kg
  • Clinician-selected protein factor in g/kg/day

Clinical interpretation

The output states the amount implied by the inputs. It is not evidence that the selected factor is appropriate for renal disease, burns, critical illness or a particular body-composition goal.

Worked example

At 70 kg and 1.2 g/kg/day, the amount is 84 g/day. If the chosen assessment weight is instead 60 kg, the same factor gives 72 g/day. The 12-g difference shows why the weight convention must be documented.

Limitations and safety notes

Energy adequacy, tolerance, organ function and overall nutritional assessment are not modeled. The accepted numeric range is not a list of recommended prescriptions, and this tool does not choose a supplement or feeding route.

Frequently asked questions

Should I always use the scale weight?

Use the weight convention required by the applicable clinical plan. Edema or other circumstances can make an unexamined scale weight unsuitable.

References

  • https://www.nice.org.uk/guidance/cg32/chapter/Recommendations

Editorial review and citation methodology

Maintained by the Quick Medical Calculator Editorial Team. Content record date: September 9, 2026. A content date is not evidence of independent clinical review. Individual clinical sign-off is not recorded on this page.

  • Prefer original validation studies for scoring systems and prediction tools.
  • Use current specialty society guidance, transplant allocation policy, public health guidance, or regulator resources when they govern clinical use.
  • Include limitations and safety notes when a calculator is population-specific, context-dependent, or unsuitable as a standalone decision tool.

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