Glomerular Filtration Rate (GFR) is an essential measurement used to evaluate kidney function. It shows how much blood the kidneys filter each minute. Since directly measuring GFR is complex, doctors estimate it using a blood creatinine test. How to calculate GFR from creatinine, medical professionals use equations such as the CKD-EPI formula. This calculation includes serum creatinine level, age, and gender to determine the estimated GFR (eGFR), which is expressed in mL/min/1.73 m². Generally, when creatinine levels increase, GFR decreases, indicating reduced kidney function. Laboratories usually provide eGFR automatically along with creatinine results, so manual calculation is rarely needed. Monitoring eGFR regularly helps in the early detection and management of chronic kidney disease, especially in people with diabetes, high blood pressure, or a family history of kidney problems.