kdigo calculator

What is a KDIGO calculator?

A KDIGO calculator helps classify acute kidney injury (AKI) stage based on criteria from the Kidney Disease: Improving Global Outcomes (KDIGO) guideline. In day-to-day practice, clinicians combine serum creatinine trends, urine output patterns, and overall clinical context to identify AKI early.

This tool gives a quick, structured estimate of AKI stage (0–3) using the same threshold logic commonly used at the bedside. It is useful for education, chart review, and decision support—but not a replacement for clinical judgment.

KDIGO AKI criteria (quick reference)

Serum creatinine criteria

• Stage 1: 1.5–1.9× baseline OR increase of ≥0.3 mg/dL within 48 hours
• Stage 2: 2.0–2.9× baseline
• Stage 3: ≥3.0× baseline OR serum creatinine ≥4.0 mg/dL OR renal replacement therapy

Urine output criteria

• Stage 1: <0.5 mL/kg/h for 6–12 hours
• Stage 2: <0.5 mL/kg/h for ≥12 hours
• Stage 3: <0.3 mL/kg/h for ≥24 hours OR anuria for ≥12 hours

How to use this calculator

1. Enter baseline and current serum creatinine in mg/dL.
2. If known, enter the exact creatinine increase from the last 48 hours.
3. Optionally enter urine output rate and duration to stage by urine criteria.
4. Add anuria duration if relevant.
5. Mark whether renal replacement therapy has started.

The final KDIGO stage shown is the highest stage met by any criterion (creatinine, urine output, or RRT).

Interpreting the result

Stage 0 (No KDIGO AKI criteria met)

Current data do not satisfy formal AKI thresholds. Continue monitoring, especially in high-risk patients: sepsis, major surgery, volume depletion, nephrotoxin exposure, or chronic kidney disease.

Stage 1 AKI

Early AKI. This is often the best window for intervention: optimize perfusion, reassess medications, avoid nephrotoxins when possible, and repeat labs/urine monitoring.

Stage 2 AKI

Moderate AKI with increased risk of complications and progression. Escalated monitoring and diagnostic workup are usually indicated, including careful fluid, hemodynamic, and medication review.

Stage 3 AKI

Severe AKI. This stage is associated with high morbidity and may require renal replacement therapy or intensive care support depending on the overall clinical picture.

Important clinical limitations

• Creatinine is a delayed marker and may lag behind true kidney injury.
• Baseline creatinine uncertainty can change staging.
• Urine output quality depends on accurate timing and weight-based normalization.
• This calculator does not diagnose AKI cause (e.g., prerenal, ATN, obstruction, glomerular disease).
• Pediatric criteria and special populations may require additional interpretation.

Bottom line

A KDIGO calculator is a practical way to apply standardized AKI staging quickly and consistently. Use it to improve recognition and communication—but always pair the result with bedside assessment, trending data, and clinical judgment.

Educational use only. Not medical advice.