Calculadora de TFG
La guía detallada está disponible temporalmente en inglés.
How the CKD-EPI 2021 equation works
The calculator uses the race-free CKD-EPI 2021 creatinine equation: eGFR = 142 × min(Scr/κ, 1)α × max(Scr/κ, 1)−1.200 × 0.9938age, multiplied by 1.012 for female patients. Here κ is 0.7 for women and 0.9 for men, and α is −0.241 and −0.302 respectively. It replaced the 2009 equation that included a race coefficient, producing one unbiased estimate for all patients.
Reading the CKD stages
Chronic kidney disease stages run from G1 (90 mL/min/1.73 m² or more, normal or high) through G2 (60–89, mildly decreased), G3a (45–59) and G3b (30–44), G4 (15–29, severely decreased), to G5 (under 15, kidney failure). Stage alone does not define disease: a G1–G2 result only points toward CKD when paired with markers of kidney damage such as albumin in the urine. GFR also declines modestly with age in people without any disease.
Preguntas frecuentes
Why did my lab report show a different eGFR value?
Labs may still use the 2009 CKD-EPI equation, a different creatinine assay calibration, or report to different rounding. Values within about 10% of each other are effectively the same result — trends over time matter more than a single reading.
Does this calculator work for children?
No. Pediatric eGFR uses different equations based on height and creatinine (such as the Bedside Schwartz formula). Ask your pediatrician to interpret a child’s lab results.
What can make creatinine look higher than it really is?
Recent heavy exercise, red-meat meals, dehydration, and certain medications such as creatine supplements or drugs that block tubular secretion can all raise measured creatinine without any real change in kidney function.