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Estimate daily kilocalories for adult inpatients using Mifflin–St Jeor resting metabolic rate, then multiply by illustrative illness stress and low hospital activity factors. Shows kcal/kg and a 25–30 kcal/kg/day comparison band. Not indirect calorimetry, Penn State, or enteral/parenteral prescribing—pair with maintenance fluids and dietitian protocols for real orders.
Last updated: June 4, 2026
Estimated energy (teaching)
2,543 kcal/day
≈ 31 kcal/kg (actual body weight)
BMR (MSJ)
1,713
Stress × activity
1.35 × 1.1
25–30 kcal/kg band (rule-of-thumb)
2,050 – 2,460 kcal/day
Estimated 2,543 kcal/day (31 kcal/kg) exceeds a simple 30 kcal/kg ceiling (2,460 kcal/day)—review for overfeeding risk, fluid tolerance, and hyperglycemia in real care; stress factors here are illustrative.
Class I obesity and higher: many protocols adjust weight in predictive equations (for example adjusted or ideal body weight). This demo uses actual weight in Mifflin–St Jeor—confirm with a dietitian for protein-energy targets and monitoring.
Male 45 y, 82 kg, moderate stress, bed rest
2,543 kcal/d
BMR 1713 × 1.35 × 1.1
Same patient, severe stress
2,920 kcal/d
+377 vs moderate
Female 65 y, 68 kg, mild stress, chair
1,737 kcal/d
25.5 kcal/kg
Male 55 y, 115 kg, moderate stress
2,931 kcal/d
Band 2875–3450
Men: BMR = 10W + 6.25H − 5×age + 5 | Women: BMR = 10W + 6.25H − 5×age − 161
kcal/day ≈ round(BMR × stress × activity)
Demo: 82 kg, 178 cm, age 45 → BMR ≈ 1713 kcal/day
| Stress level | Multiplier | Teaching context |
|---|---|---|
| None / baseline | ×1.0 | Stable ward patient without major catabolic drive |
| Mild | ×1.2 | Minor surgery, limited infection |
| Moderate | ×1.35 | Major surgery, pneumonia, moderate trauma themes |
| Severe | ×1.55 | Sepsis, major burns, polytrauma—ICU often uses IC or Penn State instead |
| Activity | Multiplier | Note |
|---|---|---|
| Bed rest | ×1.1 | Typical acute medical floor |
| Chair / out of bed | ×1.2 | Sitting, limited transfers |
| Ward ambulation | ×1.3 | Short walks; still far below home exercise levels |
| Method | Inputs | Output | Limitation |
|---|---|---|---|
| This calculator | Sex, age, weight, height, stress, activity | BMR × stress × activity; 25–30 kcal/kg band | Illustrative multipliers; not ASPEN-prescribed |
| Indirect calorimetry (IC) | Measured VO₂/VCO₂ at bedside | Measured resting energy expenditure | Gold standard when available; not always feasible |
| Penn State (1998 / 2003) | BMR + ventilation + temperature (ventilated subsets) | ICU-oriented estimate | Requires minute ventilation; not on this page |
| 25–30 kcal/kg/day | Actual body weight only | Quick inpatient discussion range | Overfeeds some obese patients; underfeeds some hypermetabolic ICU patients |
BMR = 10×82 + 6.25×178 − 5×45 + 5 = 1713 kcal/day
Total ≈ 1713 × 1.35 × 1.1 = 2,543 kcal/day (31 kcal/kg)
25–30 kcal/kg band at 82 kg: 2,050–2,460 kcal/day
Estimated 2,543 kcal/day (31 kcal/kg) exceeds a simple 30 kcal/kg ceiling (2,460 kcal/day)—review for overfeeding risk, fluid tolerance, and hyperglycemia in real care; stress factors here are illustrative.
Total ≈ 1713 × 1.0 × 1.3 = 2,226 kcal/day (27.1 kcal/kg)
Teaching point: clinical status changes of ~300+ kcal/day are common when stress and mobility shift—schedule nutrition reassessment after major events.
Education only. Not for enteral/parenteral orders, refeeding protocols, or ICU prescriptions. Indirect calorimetry and registered dietitians determine actual targets.
For clinical nutrition, nursing, and medical school teaching
Suggested hashtags: #ClinicalNutrition #HospitalMedicine #MedEd #BMR #Calculator