Nephrology
Estimated Glomerular Filtration Rate — CKD-EPI 2021 Equation
Estimate kidney function using the 2021 CKD-EPI creatinine equation.
eGFR (CKD-EPI 2021) calculator
Result
91.7mL/min/1.73m²
G1 — Normal
How to use it
- 1
Enter serum creatinine (mg/dL). Fasting not required. Acute illness can transiently lower eGFR.
- 2
Age and sex. CKD-EPI 2021 removes race variable as per NKF/ASN joint task force.
- 3
CKD staging needs two values ≥3 months apart. Single low eGFR could be AKI.
When to use it
Calculate eGFR in all patients with potential CKD, diabetes, hypertension, or heart failure. Essential for drug dosing decisions. Required before initiating or continuing metformin, SGLT2 inhibitors, NOACs, low-molecular-weight heparin, and many nephrotoxic agents.
- CKD diagnosis and staging
- eGFR + ACR defines CKD stage (KDIGO 2024).
- Drug dosing
- Most renal drug dose adjustments reference eGFR.
- Contrast safety
- eGFR < 30: nephrology consult before contrast CT.
About the score
The estimated Glomerular Filtration Rate (eGFR) using the 2021 CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) creatinine equation is the standard method for assessing kidney function in clinical practice worldwide. The 2021 equation removed race as a variable from the original 2009 CKD-EPI formula to improve equity in CKD staging and organ transplant eligibility. eGFR is the cornerstone of KDIGO CKD staging, guides dosage adjustments for renally cleared drugs (including NOACs, antibiotics, and metformin), and determines eligibility for SGLT2 inhibitors — which are now indicated for CKD regardless of diabetes status per KDIGO 2024 guidelines.
Scoring criteria
Frequently asked questions
What is a normal eGFR level?
An eGFR ≥90 mL/min/1.73m² is considered normal kidney function (KDIGO G1 stage). Values of 60–89 represent mildly decreased function (G2). CKD is defined as eGFR <60 mL/min/1.73m² or evidence of kidney damage (such as proteinuria or haematuria) persisting for >3 months. A single low value may reflect acute injury rather than CKD.
When should I refer to nephrology based on eGFR?
KDIGO recommends nephrology referral for eGFR <30 mL/min/1.73m² (G4–G5), or for eGFR 30–44 (G3b) with a rapid rate of decline, significant proteinuria, or difficult-to-manage complications. Earlier referral (eGFR 45–59) is warranted if there are concerns about underlying cause or trajectory.
