Calculadora de TFG (CKD-EPI 2021)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
CKD-EPI 2021 sem raça
About this calculator
The GFR Calculator (CKD-EPI 2021) estimates the glomerular filtration rate, a key indicator of kidney function. It uses the CKD-EPI 2021 formula, which does not consider race, making it more equitable. GFR is expressed in mL/min/1.73m² and reflects how well the kidneys filter waste from the blood. Normal values vary by age and sex, but generally above 90 mL/min/1.73m² indicate normal kidney function.
The CKD-EPI 2021 formula uses serum creatinine, age, sex, and optionally cystatin C. Creatinine is a muscle breakdown product filtered by the kidneys. The equation adjusts for differences in creatinine production between men and women and with age. The 2021 version removed the race factor, which historically overestimated kidney function in Black individuals, correcting disparities.
When to use? This calculator is essential for assessing chronic kidney disease (CKD), adjusting doses of renally excreted drugs, and monitoring nephropathy progression. It is also used in routine check-ups, especially in people with diabetes, hypertension, or family history of kidney disease. It should not be used in acute kidney injury or in children.
Cautions: Estimated GFR may be inaccurate in extremes of muscle mass (athletes, amputees), high-meat diets, creatine use, or certain drugs (e.g., trimethoprim). Creatinine should be measured fasting and without prior intense exercise. Isolated values do not diagnose kidney disease; consult a nephrologist for full interpretation.
Frequently asked questions
What does a GFR below 60 mL/min/1.73m² mean?
It indicates moderately to severely reduced kidney function, possibly chronic kidney disease stage 3 or higher. Consult a nephrologist for evaluation.
Why does the CKD-EPI 2021 formula not use race?
Studies showed the racial adjustment overestimated kidney function in Black individuals, leading to delayed diagnosis. The 2021 version is more accurate and fair for all.
Can I use this calculator if I am pregnant?
No, estimated GFR is not accurate in pregnancy due to hemodynamic changes. Consult your obstetrician for specific assessment.
What is the difference between GFR and creatinine clearance?
GFR is estimated by formulas (like CKD-EPI), while clearance requires a 24-hour urine collection. Estimated GFR is more practical and widely used.
Does creatinine need to be measured fasting?
It is recommended to fast for 8 hours and avoid intense exercise 24 hours prior, as meat and muscle activity temporarily raise creatinine.