Clinical calculator

Estimated Needs Calculator

Adult calculation aid for estimated energy needs plus optional clinician-selected energy, protein, and basic fluid estimates.

Inputs

Method used

Mifflin-St Jeor and weight-based kcal/kg are free. Adult equation and Penn State methods require Pro.

Results

Enter valid inputs to calculate

Adult required inputs and enabled optional sections must pass guardrails before outputs are shown.

Chart-note draft

Draft text is provided for RD review and should be edited before use in clinical documentation.

Enter valid inputs to generate draft chart-note text.

Formula details

Show the math

Selected-method formula, optional estimate sections, and rounding rules.

Selected method: Mifflin-St Jeor

  • Male: REE = 9.99 × actual weight kg + 6.25 × height cm − 4.92 × age years + 5.
  • Female: REE = 9.99 × actual weight kg + 6.25 × height cm − 4.92 × age years − 161.
  • Common shorthand uses 10 and 5 coefficients; RDCalc preserves the exact coefficients above.

Method set

  • Mifflin-St Jeor and Weight-based calorie estimate (kcal/kg) are Free methods.
  • Harris-Benedict original, Revised Harris-Benedict, Owen, and Penn State methods require Pro.
  • Penn State 2003b and Penn State 2010 modified are active critical-care calculation aids requiring Tmax and minute ventilation.
  • Specialty workflows such as obesity/critical-care, renal, wound, pediatrics, and pregnancy/lactation belong in separate future Calculator Hub workflows, not this method selector.

Stress/activity

  • Stress and activity factors are optional separate fields for adult general REE/BEE equation methods only.
  • When entered for adult general methods, factor totals use the selected equation value.
  • Stress/activity factors are not applied to Weight-based calorie estimate or Penn State methods.
  • No presets are automatically selected.

Weight-based energy and protein

  • Weight-based calorie estimate is a selectable Free method, not a standalone optional add-on section.
  • Protein remains an optional estimate section and uses the selected weight basis shown in results and chart-note draft.
  • Weight-based kcal/kg and protein ranges remain clinician-selected calculation aids.

Fluid

  • mL/kg/day uses clinician-selected factors and selected weight basis.
  • 1.0 mL/kcal uses the selected equation energy, the weight-based calorie estimate when that method is selected, or manual kcal/day.
  • Fluid displays mL/day and L/day.

Rounding

  • Calculations are rounded only for displayed outputs and chart-note text.
  • Energy, protein, and mL/day outputs display as whole numbers.
  • L/day outputs display to 1 decimal place.

Transparency

Sources & assumptions

Source/version

  • Estimated Needs
  • Spec version: 2026-05-estimated-needs
  • Mifflin-St Jeor is the free/default equation.
  • Harris-Benedict original, Revised Harris-Benedict, Owen, and Penn State methods require Pro.
  • Weight-based kcal/kg ranges are clinician-selected calculation aids.
  • Penn State methods require Tmax and minute ventilation; stress/activity factors are not applied to Weight-based or Penn State outputs.
  • Specialty workflows such as obesity/critical-care, renal, wound, pediatrics, and pregnancy/lactation belong in separate future Calculator Hub workflows, not this method selector.
  • Mifflin MD, St Jeor ST, Hill LA, Scott BJ, Daugherty SA, Koh YO. A new predictive equation for resting energy expenditure in healthy individuals. Am J Clin Nutr. 1990;51(2):241-247.

Scope

  • Adults age 19+.
  • Uses user-entered values and clinician-selected factors. Critical-care estimates should be reviewed against clinical context, indirect calorimetry when available, and local policy.
  • Source/version details stay out of the copied chart-note draft.

Not designed for

  • Pediatrics/adolescents under 19
  • Pregnancy/lactation-specific calculations
  • Critical illness-specific protocols beyond implemented adult ventilated Penn State calculation aids
  • Renal/cardiac/hepatic disease-specific specialty plans
  • Fluid restriction-specific recommendations
  • Hypernatremia correction/free-water deficit
  • Malnutrition diagnosis
  • Diagnosis-based automatic nutrition plans
  • Enteral formula goal-rate analysis
  • Resuscitation or complex fluid management

Professional use

Estimated needs are calculation aids for qualified clinicians and do not replace clinical judgment, local policy, indirect calorimetry when available, or patient-specific assessment. RDCalc does not diagnose malnutrition or set a care plan.