mg/dL
mg/dL
Urine output (check the most severe that applies)
How it's calculated
AKI is staged by whichever of two criteria — serum creatinine rise or urine output — gives the more severe (higher) stage.
Staging criteria
| Stage | Serum creatinine | Urine output |
|---|---|---|
| 1 | 1.5-1.9× baseline, or ≥0.3 mg/dL rise within 48h | <0.5 mL/kg/h for 6-12h |
| 2 | 2.0-2.9× baseline | <0.5 mL/kg/h for ≥12h |
| 3 | ≥3.0× baseline, or rise to ≥4.0 mg/dL, or RRT initiated | <0.3 mL/kg/h for ≥24h, or anuria ≥12h |
Clinical use
- Used to identify and stage acute kidney injury early, standardising definitions across studies and clinical practice.
- Stage is assigned by whichever criterion (creatinine or urine output) is more severe — a patient can meet Stage 3 on urine output alone even with a smaller creatinine rise.
- Stage 3 is also automatically met by starting renal replacement therapy, regardless of the creatinine or urine-output values at that time.
Frequently asked questions
What does KDIGO stand for?
Kidney Disease: Improving Global Outcomes — the organisation that published the 2012 clinical practice guideline defining and staging acute kidney injury (AKI) used by this calculator.
What if creatinine and urine output suggest different stages?
The overall AKI stage is the higher (more severe) of the two — KDIGO staging uses whichever criterion indicates worse kidney injury, not an average.
Does starting dialysis automatically mean Stage 3 AKI?
Yes — initiation of renal replacement therapy defines Stage 3 AKI under KDIGO criteria regardless of the creatinine or urine output values at that time.
References
- Kidney Disease: Improving Global Outcomes (KDIGO) Acute Kidney Injury Work Group. KDIGO Clinical Practice Guideline for Acute Kidney Injury. Kidney Int Suppl. 2012;2:1-138.