Jelliffe Creatinine Clearance Calculator

Overview

This implementation uses a commonly cited steady-state Jelliffe equation and reports an unindexed estimate in mL/min after applying the sex factor.

Clinical Significance

The equation may be encountered in historical literature and selected pharmacokinetic work, but current practice more commonly uses CKD-EPI eGFR or Cockcroft–Gault where specified.

When to Use

• Use only where a protocol specifically requests the Jelliffe equation.
• Do not substitute it automatically for laboratory eGFR or Cockcroft–Gault.
• Use caution when serum creatinine is changing.

How It Is Calculated

• Male estimate = (98 − 0.8 × (age − 20)) ÷ serum creatinine in mg/dL; female estimate = male result × 0.9.
• Serum creatinine entered in µmol/L is converted to mg/dL by dividing by 88.4.

Interpretation

• Lower values suggest lower estimated renal clearance.
• Medicine-dosing thresholds are equation- and medicine-specific.
• Compare with the renal estimate required by the relevant protocol.

Worked Example

A 60-year-old male with creatinine 100 µmol/L has an estimated Jelliffe clearance of approximately 58.3 mL/min.

Patient Considerations

• Acute kidney injury, low muscle mass, amputation, pregnancy and unusual creatinine generation can reduce accuracy.

Limitations

• The equation is old and less commonly recommended than modern alternatives.
• It may be unreliable outside steady-state renal function.
• It should not be confused with measured creatinine clearance or indexed eGFR.

Clinical Pearls

• Document the equation used.
• Use modern laboratory eGFR or Cockcroft–Gault when the relevant guidance requires them.
• Consider measured clearance or specialist advice when precision matters.

Common Mistakes

• Entering µmol/L as mg/dL.
• Using the estimate interchangeably with CKD-EPI eGFR.
• Applying it during rapidly changing creatinine without caution.

Evidence Base

Jelliffe proposed simplified creatinine-clearance equations in the early 1970s. They remain of historical and occasional pharmacokinetic interest.

References

1. Jelliffe RW. Estimation of creatinine clearance when urine cannot be collected. Lancet. 1971;1:975–976. — Original description of a simplified creatinine-clearance estimate.
2. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. — Current international kidney-disease guidance and context for modern GFR estimation.