Bladder Scan Volume by Age

Bladder Volume Formula:

\[ V = \frac{\pi}{6} \times L \times W \times H \]

Length (L):

Width (W):

Height (H):

Patient Age:

years

Bladder Volume (cm³):

Age-Adjusted Volume (cm³):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Bladder Scan Volume by Age?

Definition: This calculator estimates bladder volume from ultrasound measurements, adjusted for age-specific norms.

Purpose: Helps clinicians assess bladder capacity and detect abnormalities like urinary retention or overactive bladder.

2. How Does the Calculator Work?

The calculator uses the ellipsoid formula:

\[ V = \frac{\pi}{6} \times L \times W \times H \]

Where:

\( V \) — Bladder volume (cm³)
\( L \) — Maximum length (cm)
\( W \) — Maximum width (cm)
\( H \) — Maximum height (cm)

Explanation: The formula approximates the bladder as an ellipsoid. Age adjustments account for normal developmental changes.

3. Importance of Bladder Volume Measurement

Details: Accurate volume assessment helps diagnose conditions, guide catheterization needs, and monitor treatment effectiveness.

4. Using the Calculator

Tips: Enter maximum dimensions from ultrasound in cm and patient age. All measurements must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is the ellipsoid formula?
A: It's about 90% accurate for regular bladder shapes but may underestimate irregular volumes.

Q2: What are typical age-adjusted volumes?
A: Adult capacity is ~400-600mL; children: (Age + 1) × 30mL up to 12 years.

Q3: When is post-void residual important?
A: Volumes >100mL in adults or >20% capacity in children may indicate retention.

Q4: How do I measure bladder dimensions?
A: Use ultrasound to get maximum sagittal (L), transverse (W), and anterior-posterior (H) diameters.

Q5: Does this account for bladder shape variations?
A: No, the formula assumes regular ellipsoid shape. Actual scanning software may use more complex algorithms.