eGFR Kidney Function Calculator
Calculate your estimated glomerular filtration rate (eGFR) using the 2021 CKD-EPI equation (race-free). Enter serum creatinine, age, and sex to stage kidney function from G1 (normal) to G5 (kidney failure). Free and private.
Key Capabilities
CKD-EPI 2021 race-free equation
Uses the 2021 CKD-EPI equation — the current clinical standard that removed race as a variable to improve equity in kidney disease staging across all patient populations.
CKD G1 to G5 staging with plain-English descriptions
Outputs both the numeric eGFR value and the corresponding KDIGO CKD stage label (G1 through G5) with a description of what that stage means for kidney function and clinical management.
mg/dL creatinine input with unit conversion note
Accepts serum creatinine in mg/dL with a visible note for patients whose lab reports use micromol/L (UK, Australia) — divide by 88.4 to convert to mg/dL before entering.
How to Use
Enter serum creatinine in mg/dL
Find the creatinine on your lab report. If it is in micromol/L, divide by 88.4 first to convert it to mg/dL before entering.
Enter age and select sex
Type your age in years and select biological sex — both are variables in the CKD-EPI 2021 equation.
Read your eGFR and CKD stage
The calculated eGFR and KDIGO stage (G1 through G5) appear immediately. Share the result with your nephrologist or GP for clinical interpretation and management planning.
Common Use Cases
- Nephrologists staging new referralsA nephrologist receiving a GP referral quickly calculates eGFR from the enclosed creatinine value to confirm the CKD stage and triage appointment urgency before the patient is seen.
- Diabetic patients monitoring kidney functionA person with Type 2 diabetes who receives annual kidney function tests enters their creatinine value and understands their CKD stage without waiting for a doctor's interpretation of the lab report.
- Hospital pharmacists adjusting renal drug dosesA clinical pharmacist calculates eGFR to determine whether renal dose adjustment is required for drugs such as metformin, antibiotics, or anticoagulants before dispensing.
Frequently Asked Questions
What is eGFR and why does it matter?
Estimated Glomerular Filtration Rate (eGFR) measures how well your kidneys filter waste from the blood. It is expressed in mL/min/1.73m² and is the primary test used to stage chronic kidney disease (CKD). A declining eGFR over time indicates worsening kidney function.
What are the CKD stages by eGFR?
G1: ≥90 — Normal or high. G2: 60–89 — Mildly decreased. G3a: 45–59 — Mildly to moderately decreased. G3b: 30–44 — Moderately to severely decreased. G4: 15–29 — Severely decreased. G5: <15 — Kidney failure.
What is the CKD-EPI 2021 equation?
CKD-EPI 2021 is the most accurate race-free equation for estimating GFR from serum creatinine in adults. It replaced earlier equations that included race as a variable. The formula uses serum creatinine, age, and sex to calculate eGFR.
What serum creatinine unit should I use?
This calculator uses mg/dL, which is the standard unit in India and the United States. If your lab report shows creatinine in μmol/L (UK/Australia), divide by 88.4 to convert to mg/dL first.
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