eGFR Calculator

Calculate estimated Glomerular Filtration Rate using the CKD-EPI 2021 equation.

Important Clinical Disclaimer: The eGFR Calculator is intended for use by qualified healthcare professionals only. It is for educational and informational purposes and should not replace clinical judgement. Always interpret results alongside the full clinical picture and follow your local guidelines and protocols.
Patient Details
CKD Stages Reference
Stage eGFR (mL/min/1.73m²) Description Action
G1 ≥90 Normal or high Monitor if other kidney markers abnormal
G2 60-89 Mildly decreased Monitor, assess CVD risk
G3a 45-59 Mildly to moderately decreased Monitor 1-2x yearly, manage risk factors
G3b 30-44 Moderately to severely decreased Monitor 2-3x yearly, nephrology referral may be needed
G4 15-29 Severely decreased Nephrology referral, prepare for RRT
G5 <15 Kidney failure Renal replacement therapy may be needed
About eGFR
What is eGFR?

Estimated Glomerular Filtration Rate (eGFR) measures how well your kidneys filter waste from your blood. It's calculated from serum creatinine, age, and sex using validated equations.

CKD-EPI 2021 Equation

This calculator uses the CKD-EPI 2021 equation, which was developed to provide more accurate estimates across diverse populations without using race as a variable. This is the equation recommended by NICE and UK Kidney Association.

Limitations
  • Less accurate in certain populations (very muscular, amputees, malnourished)
  • May be affected by diet, medications, and muscle mass
  • Not validated in children under 18
  • Acute kidney injury requires different assessment
NHS Resources
Creatinine Conversion

To convert between units:

µmol/L to mg/dL:

mg/dL = µmol/L ÷ 88.4

mg/dL to µmol/L:

µmol/L = mg/dL × 88.4

Normal ranges:

  • Female: 45-90 µmol/L
  • Male: 60-110 µmol/L
Related Calculators
Need Help?

If you're concerned about your kidney health:

  • Contact your GP
  • NHS 111 for non-emergency advice
  • Kidney Care UK helpline
Disclaimer

This calculator is provided for educational and informational purposes only. It is not intended to be a substitute for professional medical advice, diagnosis, or treatment.

  • Always seek the advice of a qualified healthcare provider with any questions regarding a medical condition.
  • Never disregard professional medical advice or delay seeking it because of information from this tool.
  • Clinical decision-making should always incorporate the full clinical context, patient preferences, and local protocols.
  • The creators of this tool accept no liability for decisions made based on its output.

If you are a patient: please discuss any results with your healthcare provider. This tool is designed for use by medical professionals and may not be appropriate for self-assessment.