FENA (Fractional Excretion of Sodium) Calculator

Urine Sodium (mEq/L):

Plasma Sodium (mEq/L):

Urine Creatinine (mg/dL):

Plasma Creatinine (mg/dL):

Description

The **Fractional Excretion of Sodium (FENA)** is a calculation used to evaluate renal function, especially in patients with acute kidney injury. It indicates the percentage of the sodium filtered by the kidney which is excreted in the urine.

How to Use

Enter the urine sodium concentration in mEq/L.
Enter the plasma sodium concentration in mEq/L.
Enter the urine creatinine concentration in mg/dL.
Enter the plasma creatinine concentration in mg/dL.
Click the "Calculate FENA" button to determine the fractional excretion of sodium.
The result will be displayed below the button, showing the FENA percentage.

How to Calculate FENA Manually

To manually calculate FENA, use the following formula:

**Formula:** FENA (%) = [(Urine Sodium × Plasma Creatinine) / (Plasma Sodium × Urine Creatinine)] × 100
Multiply urine sodium by plasma creatinine.
Multiply plasma sodium by urine creatinine.
Divide the result from step 2 by the result from step 3.
Multiply the quotient by 100 to get the FENA percentage.
Example: If urine sodium is 50 mEq/L, plasma sodium is 140 mEq/L, urine creatinine is 100 mg/dL, and plasma creatinine is 1.2 mg/dL:
- FENA = [(50 × 1.2) / (140 × 100)] × 100
- FENA = (60 / 14000) × 100 ≈ 0.43%