Health

FENa Calculator

Differentiate pre-renal from intrinsic AKI.

Serum Na⁺ (mEq/L)

Urine Na⁺ (mEq/L)

Serum Creatinine (mg/dL)

Urine Creatinine (mg/dL)

FENa—

Interpretation—

FENa = (UNa × SCr) / (SNa × UCr) × 100
<1%: Pre-renal | >2%: Intrinsic (ATN) | 1–2%: Indeterminate