Calculadora TFG Online Grátis
Glomerular filtration rate (kidney function) using CKD-EPI formula
Glomerular Filtration Rate (GFR) measures how well your kidneys are filtering waste from the blood — the key indicator of kidney function used to stage chronic kidney disease (CKD). This calculator uses the CKD-EPI formula (the current clinical standard) to estimate your eGFR from serum creatinine, age, and sex.
Frequently Asked Questions
Sobre Esta Calculadora
The glomerular filtration rate is the volume of fluid filtered by the kidneys per unit time — measured in milliliters per minute per 1.73 m² of body surface area. Because directly measuring GFR requires infusing traceable substances, clinical practice uses estimated GFR (eGFR) derived from serum creatinine, a metabolic waste product the kidneys normally clear.
The CKD-EPI equation (Chronic Kidney Disease Epidemiology Collaboration, 2021 revision) is the current KDIGO guideline-recommended formula. It replaced the older MDRD formula because it's more accurate at higher GFR values (above 60). The 2021 race-free version removed race as a variable, following concerns that the prior coefficient created health disparities.
GFR naturally declines with age — typically by about 1 mL/min/1.73m² per year after age 40. Values above 90 are normal; 60–89 indicates mildly decreased function; below 60 for more than 3 months defines CKD. This calculator is intended for informational awareness, not clinical diagnosis — consult your doctor for interpretation of your creatinine results.
Calcula a TFG para avaliar a função renal.
Exemplo Resolvido
eGFR calculation for a 58-year-old woman with creatinine of 1.1 mg/dL
Entradas:
- Age: 58
- Sex: Female
- Serum creatinine: 1.1 mg/dL
Passo a Passo:
- CKD-EPI formula (female, creatinine > 0.7 mg/dL):
- eGFR = 142 × (Cr/0.7)^-1.200 × (0.9938)^Age × 1.012
- = 142 × (1.1/0.7)^-1.200 × (0.9938)^58 × 1.012
- = 142 × (1.571)^-1.200 × 0.6988 × 1.012
- = 142 × 0.601 × 0.6988 × 1.012 ≈ 60.3 mL/min/1.73m²