eGFR/CKD Stage Calculator

KDIGO 2024 Guidelines - GFR & Albuminuria Classification

Calculate estimated glomerular filtration rate (eGFR) using the 2021 CKD-EPI creatinine equation and classify chronic kidney disease (CKD) stage according to KDIGO 2024 guidelines using both GFR category (G1-G5) and albuminuria category (A1-A3).

KDIGO CKD Classification System

GFR Categories (G1-G5):

  • G1: ≥90 (Normal or high)
  • G2: 60-89 (Mildly decreased)
  • G3a: 45-59 (Mild-moderate decrease)
  • G3b: 30-44 (Moderate-severe decrease)
  • G4: 15-29 (Severely decreased)
  • G5: <15 (Kidney failure)

Albuminuria Categories (A1-A3):

  • A1: <30 mg/g (Normal-mild)
  • A2: 30-299 mg/g (Moderately increased)
  • A3: ≥300 mg/g (Severely increased)

UACR = Urine Albumin-to-Creatinine Ratio

Patient Information

Demographics

2021 CKD-EPI equation (race coefficient removed in updated version)

Laboratory Values

Normal: 0.6-1.2 mg/dL (varies by lab)

Urine Albumin-to-Creatinine Ratio (optional but recommended)

About CKD & eGFR

What is eGFR?

Estimated glomerular filtration rate (eGFR) is the best overall indicator of kidney function. It's calculated from serum creatinine, age, and sex using validated equations like CKD-EPI. eGFR estimates how much blood passes through the glomeruli (kidney filters) each minute.

Why UACR Matters

The urine albumin-to-creatinine ratio (UACR) detects kidney damage even when eGFR is normal. Albuminuria indicates damaged kidney filters and is an independent predictor of CKD progression and cardiovascular disease. KDIGO guidelines require both GFR and albuminuria for complete CKD staging.

CKD Definition

Chronic kidney disease is defined as abnormalities of kidney structure or function, present for >3 months, with implications for health. This includes eGFR <60 mL/min/1.73m² OR markers of kidney damage (albuminuria, structural abnormalities, etc.) for >3 months.

2021 CKD-EPI Equation Update

The 2021 CKD-EPI creatinine equation removed the race coefficient from the 2009 equation, addressing concerns about using race in medical algorithms. This calculator uses the updated race-free equation, which provides more equitable kidney function assessment.

When to Suspect CKD

  • Diabetes mellitus (leading cause)
  • Hypertension (second leading cause)
  • Family history of kidney disease
  • Age >60 years
  • Cardiovascular disease
  • Obesity (BMI ≥30)
  • Autoimmune diseases (lupus, vasculitis)
  • Recurrent urinary tract infections
  • Kidney stones
  • Prolonged use of nephrotoxic medications (NSAIDs, certain antibiotics)