- Select the uACR units (mg/g or mg/mmol) to match the laboratory report, and the calibration — use Non-North American outside the U.S. and Canada.
- Enter age and select sex.
- Enter the most recent eGFR (the equation is validated for eGFR < 60).
- Enter the urine albumin-to-creatinine ratio (a positive value is required for the logarithm term).
- The 2-year and 5-year risks update live, with a risk band (low / intermediate / high) and suggested next steps.
All computation runs in your browser; no values are stored or transmitted.
When to Use
Use the Kidney Failure Risk Equation (KFRE) to quantify the absolute risk that an adult with CKD G3–G5 will progress to kidney failure — defined as dialysis or transplantation — within 2 and 5 years. The 4-variable model uses age, sex, eGFR, and urine albumin-to-creatinine ratio (uACR). It converts a vague clinical impression of "high risk" into a calibrated probability that supports referral timing, vascular-access planning, and transplant work-up, and helps patients understand their trajectory.
Appropriate population
Adults with CKD categories G3a–G5 not yet on kidney replacement therapy, with a recent eGFR and a quantified urine albumin-to-creatinine ratio. Particularly useful when deciding whether and when to refer to nephrology, when to create dialysis access, and when to begin transplant evaluation. KDIGO endorses risk-based thresholds (e.g., a 5-year risk above a defined cut-point) to guide referral and multidisciplinary care.
When NOT to use it
The 4-variable KFRE is not validated and does not apply to patients already on dialysis or with a functioning kidney transplant, to acute kidney injury, or to children. It predicts kidney failure — not death or cardiovascular events, which often occur first in older patients with CKD. A urine ACR is required; using a dipstick or protein-to-creatinine surrogate degrades accuracy. Apply the calibration appropriate to your region.
Pearls & Pitfalls
Risk beats threshold for timing
Plan dialysis access and transplant referral by calculated risk, not by a fixed eGFR. A patient with a high 2-year KFRE benefits from early arteriovenous fistula creation even if the eGFR has not yet reached a traditional trigger.
Use the right calibration and a true ACR
Apply the non-North American calibration outside the U.S. and Canada, and always use a quantitative urine albumin-to-creatinine ratio. Substituting a dipstick or a protein-to-creatinine ratio reduces accuracy. Re-run the equation as eGFR and albuminuria evolve.
Pitfalls
(1) The KFRE does not apply to dialysis or transplant patients, AKI, or children. (2) It predicts kidney failure only — many older or comorbid patients die of cardiovascular disease before reaching dialysis, so always weigh competing risk. (3) A very low or zero uACR cannot be entered (the model takes the logarithm of uACR); use the lowest measured positive value. (4) The estimate is population-derived and must be individualized.
Why Use It
Two patients with the same eGFR can have very different futures: the one with heavy albuminuria progresses far faster. The KFRE integrates the four strongest, routinely available predictors into a single calibrated risk, which outperforms eGFR alone for timing decisions. Risk-based planning — rather than eGFR-threshold planning — reduces unplanned dialysis starts and central-venous-catheter use, supports earlier pre-emptive transplant referral, and gives patients a concrete, shared basis for decisions. The equation has been externally validated across more than 30 countries and over 700,000 patients.
Kidney Failure Risk Equation (KFRE) — 2-Year & 5-Year Risk
Enter age, sex, eGFR, and urine albumin-to-creatinine ratio. Select the uACR units and the calibration (use non-North American outside the U.S./Canada) to estimate 2-year and 5-year risk of kidney failure.
⚕ 4-variable Kidney Failure Risk Equation (Tangri et al., JAMA 2011; multinational recalibration, Tangri et al., JAMA 2016). Risk = 1 − S0^exp(L), where L = −0.2201×(age/10 − 7.036) + 0.2467×(male − 0.5642) − 0.5567×(eGFR/5 − 7.222) + 0.4510×(ln(uACR mg/g) − 5.137). Default uses the non-North American calibration (S0 2yr = 0.9832, 5yr = 0.9365); North American calibration uses S0 2yr = 0.9751, 5yr = 0.9240. SI conversion: 1 mg/mmol ≈ 8.84 mg/g. This equation does NOT apply to patients already on dialysis or with a kidney transplant, and predicts kidney failure — not death or cardiovascular events. It is a population-derived estimate and requires physician interpretation in your individual clinical context.
Next Steps
Use the result to support — not replace — clinical judgment.
- Interpret the value against the targets shown in the calculator and the Evidence section below, in the context of the full clinical picture.
- Trend serial measurements rather than acting on a single result; confirm abnormal or unexpected values before changing management.
- Apply the relevant KDIGO / specialty-guideline threshold and document the indication.
- Escalate or refer to nephrology when results are out of range, rapidly changing, or discordant with the clinical picture — and discuss the implications with the patient.
Evidence & References
Formula & Equations
The 4-variable KFRE estimates risk over time t as Risk = 1 − S₀(t)exp(L), where L is the linear predictor and S₀(t) is the baseline survival.
| Component | Expression |
|---|---|
| Linear predictor (L) | −0.2201 × (age/10 − 7.036) + 0.2467 × (male − 0.5642) − 0.5567 × (eGFR/5 − 7.222) + 0.4510 × (ln(uACR in mg/g) − 5.137) |
| male | 1 if male, 0 if female |
| Risk at time t | 1 − S₀(t)exp(L) |
| SI conversion | uACR (mg/g) = uACR (mg/mmol) × 8.84 |
Baseline survival (S₀) by calibration
| Calibration | S₀ at 2 years | S₀ at 5 years |
|---|---|---|
| Non-North American (2016 recalibration) | 0.9832 | 0.9365 |
| North American (original) | 0.9751 | 0.9240 |
The non-North American recalibration (Tangri 2016) corrected systematic miscalibration observed outside North America and is the appropriate default for Philippine practice.
Evidence & References
The KFRE was derived and internally validated by Tangri and colleagues in 2011, then externally validated and recalibrated across more than 30 countries in a 2016 multinational study, which confirmed excellent discrimination and provided region-specific baseline survival. KDIGO 2024 endorses validated risk equations such as the KFRE to guide nephrology referral and kidney-failure planning.
- Tangri N, Stevens LA, Griffith J, et al. A Predictive Model for Progression of Chronic Kidney Disease to Kidney Failure. JAMA. 2011;305(15):1553–1559.
- Tangri N, Grams ME, Levey AS, et al. Multinational Assessment of Accuracy of Equations for Predicting Risk of Kidney Failure: A Meta-analysis. JAMA. 2016;315(2):164–174.
- Kidney Disease: Improving Global Outcomes (KDIGO) CKD Work Group. KDIGO 2024 Clinical Practice Guideline for the Evaluation and Management of Chronic Kidney Disease. Kidney Int. 2024;105(4S):S117–S314.
