Calculator
eGFR Calculator
Estimated glomerular filtration rate with KDIGO staging and dosing guidance.
Estimated GFR · Stage G3b
42.5mL/min/1.73m²
Moderate-to-Severe Reduction — Very High Risk
Patient
These equations are validated in adults only.
CKD-EPI 2021 is the current standard.
Raises the risk category at any eGFR.
Try a typical patient
Both equations
Shown side by side so they can be compared.
Stage G3b — Moderate-to-Severe Reduction
Monitoring
Monitor eGFR, potassium, bicarbonate, and CBC every 3–6 months.
Management
Nephrology consultation recommended. Metformin max 1000 mg/day. Adjust renally cleared drugs (DOACs, antibiotics). Avoid NSAIDs.
CKD-EPI 2021: eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^−1.200 × 0.9938^age × 1.012 (if female)
κ is 0.7 for females and 0.9 for males; α is −0.241 for females and −0.302 for males. The 2021 refit removed the race coefficient that earlier equations applied.
MDRD: eGFR = 175 × Scr^−1.154 × age^−0.203 × 0.742 (if female)
eGFR estimates kidney function from creatinine, which depends on muscle mass — so it is less reliable at extremes of body composition, in acute kidney injury, and in pregnancy. Staging combines eGFR with albuminuria (uACR), which is why A2 or A3 raises the risk category even when eGFR looks acceptable.
Standards: 2021 NKF-ASN Joint Task Force (race-free eGFR); KDIGO 2024 CKD guideline.
Common questions
CKD-EPI 2021. It is the current NKF-ASN standard, is more accurate above 60 mL/min/1.73m², and removed the race coefficient that earlier equations applied. MDRD is kept here because many older records and studies quote it.
They measure different things. eGFR describes filtration rate; albuminuria describes filter damage. KDIGO stages CKD on both axes, so a patient with a near-normal eGFR but heavy albuminuria can still sit in a high-risk category.
Check the product literature. Many older drug labels were written against Cockcroft-Gault creatinine clearance, which is not the same quantity as eGFR. For drugs with a narrow margin, use whichever the label specifies rather than assuming they are interchangeable.
eGFR is normalised to an average adult body surface area so results are comparable between people. For dosing in patients at the extremes of body size, the de-indexed value in mL/min may be more appropriate.
No. CKD requires the abnormality to persist for at least three months. A single low eGFR may reflect acute kidney injury, dehydration or a transient cause, and should be repeated before staging anyone.
Prepared by the PharmaWallah student team. Verify results with your textbook or instructor. Report an error · Editorial policy