Calculator CKD Stage

CKD-EPI Equation:

\[ eGFR = 142 \times \min(Scr/\kappa, 1)^\alpha \times \max(Scr/\kappa, 1)^{-1.200} \times 0.9938^{age} \times (1.012 \text{ if female}) \]

Estimated GFR (eGFR):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is CKD Stage Calculator?

The CKD Stage Calculator estimates glomerular filtration rate (GFR) using the CKD-EPI equation and classifies the result into appropriate chronic kidney disease stages based on established clinical guidelines.

2. How Does the Calculator Work?

The calculator uses the CKD-EPI equation:

\[ eGFR = 142 \times \min(Scr/\kappa, 1)^\alpha \times \max(Scr/\kappa, 1)^{-1.200} \times 0.9938^{age} \times (1.012 \text{ if female}) \]

Where:

\( Scr \) — Serum creatinine (mg/dL)
\( \kappa \) — 0.7 (female) or 0.9 (male)
\( \alpha \) — -0.241 (female) or -0.302 (male)
\( age \) — Age in years
1.012 — Female multiplier

CKD Staging Classification:

Stage 1: eGFR ≥90 mL/min/1.73m²
Stage 2: eGFR 60-89 mL/min/1.73m²
Stage 3: eGFR 30-59 mL/min/1.73m²
Stage 4: eGFR 15-29 mL/min/1.73m²
Stage 5: eGFR <15 mL/min/1.73m²

3. Importance of CKD Staging

Details: CKD staging is essential for determining disease severity, guiding treatment decisions, monitoring disease progression, and predicting patient outcomes. Accurate staging helps in appropriate referral to nephrology services and timing of renal replacement therapy.

4. Using the Calculator

Tips: Enter serum creatinine in mg/dL, age in years, and select gender. All values must be valid (creatinine > 0, age between 1-120). The calculator will provide both eGFR value and corresponding CKD stage.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between CKD stages?
A: CKD stages represent progressively worsening kidney function, with Stage 1 being mild kidney damage with normal GFR, and Stage 5 representing kidney failure requiring dialysis or transplant.

Q2: How often should CKD staging be performed?
A: Frequency depends on the stage and stability of kidney function. Generally, Stage 1-2: annually; Stage 3: every 6-12 months; Stage 4-5: every 3-6 months or more frequently if unstable.

Q3: Can CKD stage improve?
A: While CKD is generally progressive, early stages may stabilize or show mild improvement with appropriate treatment of underlying causes and risk factor management.

Q4: What factors besides eGFR determine CKD stage?
A: Albuminuria (protein in urine) is equally important. CKD staging should consider both GFR and albuminuria categories according to KDIGO guidelines.

Q5: When should I see a nephrologist?
A: Referral is recommended for Stage 4-5 CKD, rapid progression, difficult-to-control hypertension, significant proteinuria, or when the cause of CKD is uncertain.