Calculators · Nephrology · Classification

KDIGO acute kidney injury stage

Also called AKI staging, KDIGO AKI

Stages AKI 1–3 from the rise in serum creatinine and from urine output (KDIGO 2012).

Known or presumed within the prior 7 days.

Urine output

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Formula and scoring

Stage 1: Cr 1.5–1.9× baseline or ≥0.3 mg/dL rise; UO <0.5 mL/kg/h 6–12 h. Stage 2: 2.0–2.9×; UO <0.5 for ≥12 h. Stage 3: ≥3.0×, or Cr ≥4.0 mg/dL (353.6 µmol/L), or RRT started, or (<18 y) eGFR <35; UO <0.3 for ≥24 h or anuria ≥12 h.

Exam and ward pearls

  • Two time windows: a 0.3 mg/dL rise within 48 h, or a 1.5-fold rise within 7 days.
  • Stage by whichever criterion (creatinine or urine output) gives the higher stage.

When not to rely on it

  • This calculator applies the ≥ 4.0 mg/dL stage-3 criterion only when an AKI creatinine criterion is also met, so stable CKD is not labelled AKI.

Source

  1. 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):1-138. Recommendations 2.1.1-2.1.2 and Table 2. Link

Formula and cut-offs checked against these sources on 8 Nov 2026. Educational tool for clinicians; it does not replace clinical judgement.

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