Clinical Creatinine Clearance Calculator

Creatinine Clearance Formula:

\[ CrCl = \frac{U_{cr} \times V}{P_{cr} \times t} \]

Urine Creatinine (U_cr):

mg/dL

Urine Volume (V):

Plasma Creatinine (P_cr):

mg/dL

Collection Time (t):

min

Creatinine Clearance (CrCl):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Creatinine Clearance?

Creatinine clearance is a measure of the glomerular filtration rate (GFR) calculated from urine and plasma creatinine concentrations over a specific time period. It provides a direct assessment of kidney function by measuring how effectively the kidneys clear creatinine from the blood.

2. How Does the Calculator Work?

The calculator uses the standard creatinine clearance formula:

\[ CrCl = \frac{U_{cr} \times V}{P_{cr} \times t} \]

Where:

\( U_{cr} \) — Urine creatinine concentration (mg/dL)
\( V \) — Urine volume collected (mL)
\( P_{cr} \) — Plasma creatinine concentration (mg/dL)
\( t \) — Collection time in minutes

Explanation: This formula calculates the volume of plasma cleared of creatinine per minute, providing a direct measurement of renal function.

3. Importance of Creatinine Clearance

Details: Creatinine clearance is essential for assessing kidney function, monitoring renal disease progression, adjusting medication dosages for renally excreted drugs, and evaluating transplant kidney function.

4. Using the Calculator

Tips: Enter urine creatinine in mg/dL, urine volume in mL, plasma creatinine in mg/dL, and collection time in minutes. All values must be positive numbers. For 24-hour collections, use 1440 minutes.

5. Frequently Asked Questions (FAQ)

Q1: What is the difference between creatinine clearance and eGFR?
A: Creatinine clearance is measured directly from urine collection, while eGFR is estimated from serum creatinine using equations. CrCl is more accurate but requires urine collection.

Q2: What are normal creatinine clearance values?
A: Normal values are approximately 95-125 mL/min for men and 85-115 mL/min for women, varying with age, muscle mass, and body size.

Q3: How should urine be collected for accurate measurement?
A: 24-hour urine collection is standard. Start with an empty bladder, collect all urine for 24 hours, and end with a final void. Keep refrigerated during collection.

Q4: What factors can affect creatinine clearance results?
A: Incomplete urine collection, meat consumption, exercise, medications, muscle mass, and hydration status can all influence results.

Q5: When is creatinine clearance preferred over eGFR?
A: CrCl is preferred for drug dosing adjustments, in patients with extreme body sizes, amputees, and when precise renal function assessment is critical.