eGFR Calculator (CKD Stages)

Calculate your estimated Glomerular Filtration Rate (eGFR) and CKD Stage using the CKD-EPI (2021) or MDRD equations.

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Input Parameters

Enter details for calculation.

Estimated GFR (CKD-EPI)

95 mL/min/1.73m²
Stage G1 - Normal
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Expert Tip

The 2021 CKD-EPI equation does not include a race coefficient. eGFR < 60 mL/min/1.73m² for ≥ 3 months defines Chronic Kidney Disease.

Calculation Methodology & Details

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Formula

CKD-EPI (2021) = 142 × min(Scr/κ, 1)ᵅ × max(Scr/κ, 1)⁻¹.²⁰⁰ × 0.9938^Age [× 1.012 if female]

κ = 0.7 (female) or 0.9 (male); α = -0.241 (female) or -0.302 (male).Scr = serum creatinine.

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Important Disclaimer

The calculations provided are for educational and general informational purposes only. They do not replace professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider.

How eGFR is Calculated

Follow these steps to use this calculator:

1

Input Labs & Age

Enter creatinine level, age, and biological sex.

2

Read Stage

Verify stage G1 (normal) to G5 (kidney failure).

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Detailed Insights & Expert Guide

ℹ️ About this Calculation

This nephrology and urology clinical calculator evaluates renal function, electrolyte/acid-base equilibrium, urinary excretion kinetics, and urologic disease risk according to KDIGO and AUA clinical practice guidelines.

Variable Glossary

Input

Renal & Lab Metrics

Serum creatinine, urinary sodium/urea, albumin, PSA levels, or ultrasound kidney dimensions.

Parameter

Diagnostic Indexes

eGFR (CKD-EPI equation), Fractional Excretion of Sodium (FENa %), serum anion gap, and PSA doubling kinetics.

How to Calculate Step-by-Step

1

Step 1

Enter serum electrolytes, creatinine, or urinary excretion lab values.

2

Step 2

Specify patient demographic parameters (age, gender, height/weight).

3

Step 3

View calculated clearance rates, CKD stage classification, or acute kidney injury (AKI) differentiation.

FAQ

How is FENa used to evaluate acute kidney injury (AKI)?
Fractional Excretion of Sodium (FENa) under 1% suggests prerenal azotemia (kidney hypoperfusion), whereas FENa greater than 2% indicates intrinsic acute tubular necrosis (ATN).
Which eGFR equation is recommended by current KDIGO guidelines?
The CKD-EPI (2021) race-free serum creatinine formula is the preferred standard for staging Chronic Kidney Disease (CKD Stages 1 through 5).
Can nephrology tools replace comprehensive medical diagnostics?
No. Renal and urologic calculators assist clinical decision-making. Comprehensive assessment requires complete urinalysis, renal imaging, and evaluation by a board-certified nephrologist or urologist.