eGFR (CKD-EPI 2021), CKD stage, and creatinine clearance — the three kidney function calculations your GP uses, in one place
Cockcroft-Gault formula — used for drug dosing (e.g. antibiotics, anticoagulants, direct oral anticoagulants)
Enter an eGFR value to see the CKD stage, or use the reference table below.
| Stage | eGFR (mL/min/1.73m²) | Description | Typical management |
|---|---|---|---|
| G1 | ≥ 90 | Normal or high | Monitor risk factors; treat cause |
| G2 | 60–89 | Mildly decreased | Annual review; BP and lifestyle |
| G3a | 45–59 | Mildly to moderately decreased | 6-monthly review; consider nephrology |
| G3b | 30–44 | Moderately to severely decreased | Nephrology referral; medication review |
| G4 | 15–29 | Severely decreased | Nephrology; prepare for renal replacement |
| G5 | < 15 | Kidney failure | Dialysis or transplant planning |
eGFR (CKD-EPI 2021) — use for diagnosing and staging chronic kidney disease, monitoring progression, and reporting. This is the standard in Australian pathology reports since 2005.
Creatinine clearance (Cockcroft-Gault) — use for drug dosing. Most renal drug dosing guidelines were developed using Cockcroft-Gault, and it remains the recommended method for medication adjustments — especially for dabigatran, direct oral anticoagulants, aminoglycosides, and renally-cleared antibiotics. Your pharmacist or prescribing doctor uses CrCl for this purpose.
CKD-EPI 2021 is the current internationally recommended equation for estimating GFR from serum creatinine. It was updated in 2021 to remove the race variable that was in the 2009 version — making it race-free and applicable to all patients without requiring racial self-identification. Kidney Health Australia endorses CKD-EPI 2021 as the standard equation for Australian labs.
A mildly reduced eGFR (45–59, G3a) is common in older adults and does not always indicate significant kidney disease, especially if it is stable over time. A single low result should always be repeated in 3 months. Causes of acutely low eGFR (acute kidney injury) include dehydration, medications (NSAIDs, certain blood pressure drugs, contrast dye), infections, and heart failure — these may be reversible. Persistently low eGFR over months suggests chronic kidney disease. The most common causes in Australia are diabetes and hypertension.