Validated CKD risk equation
Kidney Failure Risk Calculator: 4-Variable KFRE
Estimate the probability of dialysis or kidney transplant within two and five years for an adult with established CKD and eGFR below 60.
This calculator is for adults with established CKD and eGFR below 60. It estimates treated kidney failure (dialysis or transplant) using age, sex, eGFR, and uACR. It is not a diagnosis, dialysis decision, or individual guarantee. Discuss the result with a nephrologist or other qualified clinician.
How this tool works
This calculator implements the original 2011 four-variable KFRE. Its linear predictor uses age, the sex term defined by the model, eGFR, and the natural logarithm of urine ACR in mg/g. It then calculates 2-year risk as 1 - 0.9750^exp(LP) and 5-year risk as 1 - 0.9240^exp(LP).
The displayed results use the original North American baseline survival calibration. A later multinational study published regional recalibrations, so a tool using different baseline constants can return a different percentage from the same four inputs. The calculator states its calibration so results can be compared correctly.
How to use it
- Use this equation only for an adult with established CKD and an eGFR below 60 mL/min/1.73 m².
- Enter age, the sex term used by the published model, a recent eGFR, and urine ACR. Select mg/g or mg/mmol exactly as reported; the calculator converts mg/mmol to mg/g.
- Discuss the percentage, its calibration, and the trend in its inputs with the treating clinician before using it in planning or referral decisions.
How to interpret the result
The outcome is treated kidney failure, defined by dialysis or kidney transplantation, over the stated time horizon. It is a population-model probability, not a diagnosis, a countdown, or a guarantee that an individual will or will not reach kidney failure.
For a transparent check, age 55, male, eGFR 30, and ACR 300 mg/g produce approximately 9.6% at two years and 27.0% at five years with this North American calibration. The automated test suite locks that reference example and the two baseline constants.
Limitations and safety
- Not for people without established CKD, children, eGFR of 60 or higher, or situations where kidney function is changing rapidly.
- Calibration and accuracy can differ by country, ancestry, care setting, competing mortality risk, and the population in which the equation is used.
- Do not infer a low, medium, or high treatment category from the percentage unless a specific current clinical pathway defines and validates that threshold.
- The result cannot determine whether or when dialysis, transplant evaluation, vascular access, or referral is appropriate for an individual.
Sources and method
Formula and interpretation checked against the following primary or authoritative sources. Editorial review date: September 9, 2026.