GFR Calculator

Last updated: July 4, 2026
Reviewed by Dr. Alana Reyes, MD

About this Calculator

Glomerular Filtration Rate (GFR) is the gold standard clinically for assessing kidney function. This calculator uses the CKD-EPI 2021 revision.

Formula & Calculations

Mathematical Formula

CKD-EPI 2021 Creatinine Equation

Adjusts for age, gender, and serum creatinine levels.

How to Calculate Step-by-Step

1

Input creatinine

Serum creatinine level in mg/dL.

2

Resolve staging

Categorize GFR result into kidney stages.

How to Use & Best Practices

Provide serum creatinine levels, age, and biological gender details.

Frequently Asked Questions

What is a normal GFR?

+

A GFR of 90 or above is considered normal kidney function.

Dr. Alana Reyes, MD, MPH Clinical Reviewer

Dr. Reyes is a board-certified endocrinologist specializing in metabolic health.

Want to learn more about this calculator?

Ask our AI assistant for explanations, formulas, or usage advice.

GFR (Kidney Function)

mg/dL
years
Gender
Estimated GFR 99 mL/min
Kidney Function Stage Stage 1 - Normal
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