What is a normal eGFR level?

A normal eGFR is ≥ 60 mL/min/1.73m² in adults. An eGFR ≥ 90 mL/min/1.73m² is categorized as G1 (normal or high). Values between 60–89 (G2) may represent mild reduction, but CKD is only diagnosed when kidney damage markers like proteinuria are also present.

What is the difference between eGFR and creatinine clearance?

Creatinine clearance (CrCl), calculated using the Cockcroft-Gault equation, estimates actual kidney clearance and is used primarily for drug dose adjustments. eGFR (CKD-EPI) adjusts for body surface area and is the preferred metric for CKD staging and monitoring. Both use serum creatinine but serve different clinical purposes.

At what eGFR should I refer to nephrology?

KDIGO guidelines recommend nephrology referral when eGFR falls below 30 mL/min/1.73m² (G4). Earlier referral (eGFR 5 mL/min/1.73m²/year), severe proteinuria, unexplained AKI, or refractory hypertension.

Can eGFR be used for drug dosing?

Many drug prescribing references use eGFR to guide dose reduction, though some (particularly US FDA labeling) still reference Cockcroft-Gault CrCl. Always check the specific drug's prescribing information. For critical drugs like vancomycin, aminoglycosides, and DOACs, consult the pharmacist for the appropriate GFR-based dose calculation.

Why did the 2021 CKD-EPI equation remove race?

The original 2009 CKD-EPI equation included a race coefficient that increased eGFR estimates for Black patients, based on the assumption of higher average muscle mass. Subsequent research found this racial correction introduced systemic bias and was not biologically justified. The 2021 equation removes race entirely to ensure equitable care for all patients.

Medically Reviewed · CliniqWise Clinical Advisory Board — Nephrology Panel · Updated 2026-08-27

Estimated Glomerular Filtration Rate (eGFR) Calculator — CKD-EPI 2021

Calculate estimated glomerular filtration rate (eGFR) using the 2021 CKD-EPI creatinine equation to stage chronic kidney disease and guide clinical management.

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eGFR Calculator

Enter values below to calculate

Serum Creatinine*

mg/dL

IDMS-calibrated serum creatinine. 1 mg/dL = 88.4 µmol/L.

Age*

years

CKD-EPI validated for adults age 18–85 years.

Biological Sex*

This calculator is for informational and educational purposes. Results should be interpreted with clinical judgment and local guidelines.

What is eGFR (Estimated Glomerular Filtration Rate)?

The estimated Glomerular Filtration Rate (eGFR) is the gold-standard clinical metric used to assess kidney filtration function and stage chronic kidney disease (CKD). Expressed in mL/min/1.73m², eGFR represents the volume of blood the kidneys filter per minute, adjusted for body surface area. The 2021 CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) creatinine equation is the most widely recommended formula by KDIGO guidelines, replacing older MDRD equations for greater accuracy across normal and mildly reduced kidney function ranges. An eGFR ≥ 60 mL/min/1.73m² is generally considered the threshold for normal or mildly reduced kidney function, while values below 60 for more than 3 months confirm CKD.

eGFR (mL/min/1.73m²) is calculated using the CKD-EPI 2021 equation: eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^(-1.200) × 0.9938^Age × (1.012 if Female), where κ = 0.7 (female) or 0.9 (male), α = -0.241 (female) or -0.302 (male).

When to Use the eGFR Calculator

Screening and staging of chronic kidney disease (CKD) using KDIGO 2012 G-staging criteria (G1–G5) in all patients with risk factors such as diabetes, hypertension, or known kidney disease.
Drug dose adjustment for renally cleared medications including NSAIDs, metformin, aminoglycosides, direct oral anticoagulants (DOACs), and contrast agents before radiological procedures.
Monitoring kidney function trajectory in diabetic nephropathy, hypertensive nephrosclerosis, and glomerulonephritis during long-term management.
Pre-operative assessment to stratify surgical risk and guide anesthesia, fluid management, and post-operative care in elective and emergency procedures.
Determining eligibility for renal replacement therapy (dialysis, kidney transplant) in advanced CKD (G4–G5) and calculating residual kidney function in dialysis patients.
Evaluating safety of iodinated contrast use before CT imaging based on ACR guidelines for contrast-induced nephropathy risk.

Chronic Kidney Disease (CKD)Diabetic NephropathyHypertensive NephrosclerosisGlomerulonephritisContrast-Induced Nephropathy RiskDrug Dose AdjustmentPre-Dialysis PlanningRenal Transplant WorkupPost-AKI Follow-Up

CKD-EPI 2021 eGFR Formula & Variable Breakdown

CKD-EPI 2021 Creatinine Equation (Race-Free)

eGFR = 142 × min(Scr/κ, 1)^α × max(Scr/κ, 1)^(−1.200) × 0.9938^Age × 1.012 [if Female]

Female, 55 years, Scr = 1.2 mg/dL → eGFR ≈ 57.5 mL/min/1.73m² (CKD G3a)

Constants by Sex

Female: κ = 0.7, α = −0.241 | Male: κ = 0.9, α = −0.302

Male, 65 years, Scr = 1.5 mg/dL → eGFR ≈ 48.8 mL/min/1.73m² (CKD G3b)

Older MDRD 4-Variable Equation (Legacy)

eGFR = 175 × (Scr)^(−1.154) × Age^(−0.203) × 0.742 [if Female]

Less accurate at eGFR > 60; CKD-EPI 2021 is preferred for all clinical reporting.

Variables

Scr (Serum Creatinine) (mg/dL)

Serum creatinine measured by IDMS-calibrated assay. In µmol/L: divide by 88.4 to convert to mg/dL.

Age (years)

Patient age in whole years. CKD-EPI is validated for ages 18–85 years.

Sex (Binary (M/F))

Biological sex at birth. The 2021 equation removes race as a variable, using sex only.

κ (Kappa) (dimensionless)

Sex-specific creatinine threshold: κ = 0.7 for females, κ = 0.9 for males.

α (Alpha) (dimensionless)

Sex-specific exponent: α = −0.241 for females, α = −0.302 for males.

The CKD-EPI 2021 equation is based on IDMS-traceable creatinine assays. Laboratories that report IDMS-calibrated creatinine should use CKD-EPI 2021. The equation is validated in adults aged 18 years and older and is not applicable to pediatric patients.

CKD Staging by eGFR — KDIGO 2012 G-Stage Classification

CKD is defined as eGFR < 60 mL/min/1.73m² OR markers of kidney damage (proteinuria, hematuria) persisting for >3 months. eGFR alone defines G-stage; albuminuria A-stage provides additional prognostic information.

Range	Classification	Health Risk
≥ 90 mL/min/1.73m²	G1 — Normal or High	Normal function; if kidney damage markers present, monitor annually.
60–89 mL/min/1.73m²	G2 — Mildly Decreased	Mildly reduced; CKD only diagnosed with concurrent damage markers. Annual review.
45–59 mL/min/1.73m²	G3a — Mildly–Moderately Decreased	Optimize BP, avoid nephrotoxins. Nephrology referral if declining. 6-monthly monitoring.
30–44 mL/min/1.73m²	G3b — Moderately–Severely Decreased	Nephrology referral mandatory. Adjust renally cleared drugs. Prepare for RRT education.
15–29 mL/min/1.73m²	G4 — Severely Decreased	RRT planning (dialysis/transplant). AV fistula planning. Intensive nephrology follow-up.
< 15 mL/min/1.73m²	G5 — Kidney Failure	Kidney failure. Initiate RRT or conservative kidney management per patient choice.

All eGFR values represent steady-state kidney function. A single low eGFR reading does not confirm CKD. Two measurements at least 90 days apart are required to establish chronicity per KDIGO guidelines.

eGFR Calculator Limitations & Clinical Warnings

Not validated in acute kidney injury (AKI): CKD-EPI requires stable serum creatinine. In AKI, creatinine rises rapidly and eGFR is unreliable until steady-state is re-established.

Not applicable to pediatric patients (age < 18): Use the Bedside Schwartz equation for children. CKD-EPI is validated only for adults aged 18 years and older.

Muscle mass extremes: eGFR is inaccurate in patients with very low muscle mass (cachexia, malnutrition, spinal cord injury, amputees) or very high muscle mass (bodybuilders), as creatinine production depends on muscle.

Vegetarian and vegan diets: Dietary creatine intake affects serum creatinine. Vegetarians may have lower creatinine and thus overestimated eGFR.

Single kidney or kidney transplant: eGFR may overestimate true GFR in transplant patients. True GFR measurement (inulin clearance, iohexol) should be used where precision is critical.

Pregnancy: Glomerular filtration increases 40–65% during pregnancy. Normal eGFR in pregnancy is 110–130 mL/min/1.73m². Standard non-pregnant ranges should NOT be applied.

The 2021 CKD-EPI equation removed race as a variable. Do NOT use older race-adjusted equations in modern clinical practice.

Medical Disclaimer

This eGFR calculator is a clinical decision-support reference tool. All results must be interpreted alongside clinical history, concurrent albuminuria measurement, imaging, and trends over time. CKD staging for treatment decisions must involve nephrology specialist review.

References & Citations

Inker LA, Eneanya ND, Coresh J, et al.. “New Creatinine- and Cystatin C–Based Equations to Estimate GFR without Race (CKD-EPI 2021)”. New England Journal of Medicine. 2021. 385: 1737–1749. PMID: 34554658 | DOI: 10.1056/NEJMoa2102953
Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. “KDIGO 2012 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease”. Kidney International Supplements. 2013. 3(1): 1–150. DOI: 10.1038/kisup.2012.73
Levey AS, Stevens LA, Schmid CH, et al.. “A New Equation to Estimate Glomerular Filtration Rate (CKD-EPI)”. Annals of Internal Medicine. 2009. 150(9): 604–612. PMID: 19414839 | DOI: 10.7326/0003-4819-150-9-200905050-00006
Levey AS, Coresh J. “Chronic Kidney Disease”. The Lancet. 2012. 379(9811): 165–180. PMID: 21840587 | DOI: 10.1016/S0140-6736(11)60178-5

Medically Reviewed

Reviewed by CliniqWise Clinical Advisory Board — Nephrology Panel · Last updated: 2026-08-27 · Next review: 2027-02-27

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