Q: How often should eGFR be checked?

In high-risk individuals (diabetes, hypertension, family history of CKD), eGFR should be checked at least annually. In CKD G3a–G3b, check every 6 months. In G4, every 3 months. In G5, monthly or as clinically indicated. Acute changes in creatinine require urgent reassessment.

Q: What is the Cockcroft-Gault formula for creatinine clearance?

CrCl (mL/min) = [(140 − Age) × Weight(kg) × (0.85 if female)] ÷ (72 × Serum Creatinine in mg/dL). This formula is weight-dependent and is preferred for drug dosing calculations (e.g., antibiotics, renally-cleared chemotherapy). It is not recommended for CKD staging.

Q: Is eGFR accurate in extreme body weights or elderly patients?

CKD-EPI eGFR may be less accurate in extreme body weights (very obese or cachectic patients), elderly patients with low muscle mass (low creatinine overestimates eGFR), and patients with amputation or muscle-wasting disease. In these cases, cystatin C-based eGFR or 24-hour urine creatinine clearance is more reliable.

Question 1

What is a normal eGFR level?

Accepted Answer

A normal eGFR is ≥ 90 mL/min/1.73m² (CKD stage G1). Values between 60–89 are classified as G2 (mildly decreased but may be normal for age). An eGFR below 60 for more than 3 months indicates chronic kidney disease.

Question 2

What is the difference between eGFR and creatinine clearance?

Accepted Answer

eGFR (estimated GFR) uses serum creatinine with age and sex to estimate kidney filtration rate normalized to 1.73m² body surface area, using CKD-EPI or MDRD formulas. Creatinine Clearance (CrCl) via Cockcroft-Gault estimates actual clearance in mL/min and is weight-dependent — preferred for drug dosing. eGFR is used for CKD staging and diagnosis.

Question 3

Which formula is more accurate — CKD-EPI or MDRD?

Accepted Answer

CKD-EPI 2021 (race-free) is the currently recommended formula by KDIGO guidelines. It is more accurate than MDRD at higher eGFR values (above 60) and does not require race as an input. MDRD tends to underestimate eGFR in healthy individuals. Use CKD-EPI 2021 for diagnosis and staging; Cockcroft-Gault for drug dosing.

Question 4

How do I calculate eGFR from creatinine in µmol/L?

Accepted Answer

To convert creatinine from µmol/L to mg/dL, divide by 88.4. For example, 88.4 µmol/L equals 1.0 mg/dL. Our calculator accepts both units and converts automatically. Enter your creatinine value, select the unit, and the eGFR is computed instantly.

Question 5

What eGFR level indicates kidney failure?

Accepted Answer

An eGFR below 15 mL/min/1.73m² (CKD stage G5) indicates kidney failure (end-stage renal disease). At this level, dialysis or kidney transplantation is usually required. An eGFR of 15–29 (G4) indicates severely decreased kidney function and requires urgent nephrology referral.

Question 6

Can eGFR improve over time?

Accepted Answer

Yes, eGFR can improve with treatment of the underlying cause — controlling blood pressure, blood sugar in diabetics, treating AKI, stopping nephrotoxic drugs, or managing obstruction. However, in progressive CKD, eGFR typically declines over time. A decline of more than 5 mL/min/1.73m² per year is considered significant.

Question 7

How does CKD staging use eGFR?

Accepted Answer

KDIGO classifies CKD into G1 (≥90), G2 (60–89), G3a (45–59), G3b (30–44), G4 (15–29), and G5 (<15) based on eGFR. CKD requires eGFR below 60 or evidence of kidney damage for more than 3 months. Staging helps guide management, referral, and preparation for renal replacement therapy.

Question 8

How often should eGFR be checked?

Accepted Answer

In high-risk individuals (diabetes, hypertension, family history of CKD), eGFR should be checked at least annually. In CKD G3a–G3b, check every 6 months. In G4, every 3 months. In G5, monthly or as clinically indicated. Acute changes in creatinine require urgent reassessment.

Question 9

What is the Cockcroft-Gault formula for creatinine clearance?

Accepted Answer

CrCl (mL/min) = [(140 − Age) × Weight(kg) × (0.85 if female)] ÷ (72 × Serum Creatinine in mg/dL). This formula is weight-dependent and is preferred for drug dosing calculations (e.g., antibiotics, renally-cleared chemotherapy). It is not recommended for CKD staging.

Question 10

Is eGFR accurate in extreme body weights or elderly patients?

Accepted Answer

CKD-EPI eGFR may be less accurate in extreme body weights (very obese or cachectic patients), elderly patients with low muscle mass (low creatinine overestimates eGFR), and patients with amputation or muscle-wasting disease. In these cases, cystatin C-based eGFR or 24-hour urine creatinine clearance is more reliable.

Stage	eGFR (mL/min/1.73m²)	Description	Action
G1	`≥ 90`	Normal or high	Monitor if risk factors present
G2	`60–89`	Mildly decreased	Lifestyle modification, control BP/DM
G3a	`45–59`	Mildly to moderately decreased	Nephrology referral, adjust drug doses
G3b	`30–44`	Moderately to severely decreased	Nephrology referral, avoid nephrotoxins
G4	`15–29`	Severely decreased	Prepare for renal replacement therapy
G5	`< 15`	Kidney failure (ESKD)	Dialysis / transplant evaluation

eGFR Calculator

CKD-EPI 2021 (Race-Free) — Recommended by KDIGO

Cockcroft-Gault — Creatinine Clearance (Drug Dosing)

MDRD 4-Variable