What is the creatinine clearance for a male patient weighing 153 lb (≈69.4 kg) with serum creatinine 0.6 mg/dL, and what age is required to calculate it using the Cockcroft‑Gault equation?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: November 2, 2026 • View editorial policy

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.

Ask Question

Age is Required to Calculate Creatinine Clearance

You cannot calculate creatinine clearance without the patient's age—this is an essential variable in the Cockcroft-Gault equation, which is the standard formula for estimating CrCl in clinical practice 1.

The Cockcroft-Gault Formula

The Cockcroft-Gault equation requires four variables 1:

Estimated CrCl (ml/min) = [(140 - age) × weight] / [72 × SCr] × (0.85 if female)

Where:

  • Age is in years
  • Weight is in kg (your patient weighs 153 lb = approximately 69.4 kg)
  • SCr is serum creatinine in mg/dl (0.6 mg/dl in your case)
  • Multiply by 0.85 for females

Why Age Matters

Age is critical because creatinine clearance naturally declines with aging due to decreased muscle mass and reduced renal function 1. The formula accounts for this by subtracting age from 140—meaning a 30-year-old and an 80-year-old with identical weight and serum creatinine will have vastly different estimated creatinine clearances 1.

Example Calculations for Your Patient

For your male patient (153 lb = 69.4 kg, SCr 0.6 mg/dl):

  • If age 30: CrCl = [(140-30) × 69.4] / [72 × 0.6] = 177 ml/min
  • If age 50: CrCl = [(140-50) × 69.4] / [72 × 0.6] = 145 ml/min
  • If age 70: CrCl = [(140-70) × 69.4] / [72 × 0.6] = 113 ml/min
  • If age 85: CrCl = [(140-85) × 69.4] / [72 × 0.6] = 88 ml/min

Clinical Importance

This demonstrates why serum creatinine alone is misleading—a SCr of 0.6 mg/dl may represent normal renal function in a young adult but significant renal impairment in an elderly patient 1. The guidelines emphasize that renal function must be assessed by calculating CrCl in every patient, even when SCr is within the normal range 1.

Important Caveats

The Cockcroft-Gault formula has limitations 1:

  • Not reliable in obese or edematous patients (assumes creatinine clearance linearly reflects body weight)
  • Tends to underestimate GFR in normal and moderately reduced renal function
  • Overestimates renal function in patients with significantly impaired kidneys
  • Produces consistently low estimates in the elderly, especially the oldest patients

Request the patient's age to complete this calculation accurately.

References

Related Questions

In an 84-year-old patient weighing 68 kg with a serum creatinine of 0.8 mg/dL, is the creatinine clearance reduced?
Should I refill methocarbamol 750 mg twice daily and diclofenac 75 mg twice daily for a 61‑year‑old male on lisinopril with stable renal function (creatinine 1.09 mg/dL, eGFR ≈ 77 mL/min) and arrange appropriate follow‑up?
In a 63-year-old man with normal sinus rhythm, occasional brief palpitations, exertional dyspnea with pleuritic chest discomfort, mild renal impairment (eGFR 55 mL/min/1.73 m², creatinine 1.33 mg/dL), and blood pressure only mildly controlled on losartan 100 mg, what are the appropriate diagnostic and therapeutic steps?
What are the creatinine clearance (Cockcroft‑Gault) and estimated glomerular filtration rate (eGFR) for a 78‑year‑old female weighing 59 kg with a serum creatinine of 152 µmol/L?
In a 45-year-old female with blood urea nitrogen 7 mg/dL, estimated glomerular filtration rate 120 mL/min/1.73 m², and serum creatinine 0.46 mg/dL, are dose reductions or renal‑related contraindications required for renally cleared medications?
What are the recommended treatment strategies for avoidant/restrictive food intake disorder (ARFID)?
How common is left ventricular hypertrophy (LVH) in adults?
What are the recommended treatment regimens for cutaneous infections caused by non‑tuberculous mycobacteria such as Mycobacterium marinum, Mycobacterium ulcerans, and rapid‑growing NTM?
What is the recommended treatment plan for a 41-year-old patient with a BMI of 47 kg/m²?
In an infant born to a mother with severe hypothyroidism (TSH >150 mIU/L), what early clinical signs should be monitored?
How many days of Keflex (cephalexin) treatment are needed before clinical improvement is observed?

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.