Calculate estimated Glomerular Filtration Rate (eGFR) to assess kidney function. Uses CKD-EPI formula.
Estimate kidney function with eGFR.
The GFR (Glomerular Filtration Rate) Calculator is the gold standard for assessing kidney function. GFR measures how much blood your kidneys filter per minute, expressed in mL/min/1.73m². This value determines the stage of chronic kidney disease (CKD) and guides treatment decisions, medication dosing, and lifestyle recommendations.
Your kidneys filter approximately 180 liters of blood daily, removing waste products and excess fluid while retaining essential nutrients. When kidney function declines, waste products accumulate in the blood, leading to complications. Early detection through GFR monitoring is crucial because CKD often has no symptoms until significant damage has occurred. Risk factors include diabetes, high blood pressure, family history, and age over 60.
This calculator uses the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation, which is more accurate than older formulas like MDRD, especially for normal and mildly decreased kidney function. The formula accounts for serum creatinine, age, and sex. Race was removed from the 2021 updated formula to improve equity in clinical care.
Cr = serum creatinine in mg/dL. Results in mL/min/1.73m².
| Stage | GFR Range | Description | Action |
|---|---|---|---|
| 1 | ≥90 | Normal or high | Monitor, manage risk factors |
| 2 | 60-89 | Mildly decreased | Estimate progression |
| 3a | 45-59 | Mildly-moderately decreased | Assess complications |
| 3b | 30-44 | Moderately-severely decreased | Treat complications |
| 4 | 15-29 | Severely decreased | Prepare for kidney replacement |
| 5 | <15 | Kidney failure | Dialysis or transplant |
A 55-year-old man with creatinine of 1.2 mg/dL: eGFR ≈ 72 mL/min/1.73m² — Stage 2 CKD (mildly decreased). Annual monitoring recommended.
Related tools: Creatinine Clearance Calculator for medication dosing, BSA Calculator for body surface area, and Metabolic Syndrome Calculator for comprehensive risk assessment.
eGFR uses CKD-EPI formula: 142 × min(Cr/κ,1)^α × max(Cr/κ,1)^-1.2 × 0.9938^Age, adjusted for sex. Uses serum creatinine, age, and sex to estimate filtration rate.
Normal GFR is 90+ mL/min/1.73m². 60-89 is mildly decreased, 30-59 moderate CKD, 15-29 severe, below 15 is kidney failure requiring dialysis.
Diabetes and high blood pressure are top causes. Others: dehydration, kidney disease, certain medications, age. Low GFR doesn't always mean kidney damage—temporary factors affect it.