# Bladder Volume Calculation

Bladder volume can be estimated by ultrasound using a formula that involves width, height, length and a coefficient that depends on the bladder shape. There are few common formula for bladder volume calculation:

1.

Bladder volume = width × height × length × coefficient

The coefficient value may vary for particular methods, bladder shapes, or individual research papers. For example, it might take values of: 0.52, 0.66, 0.77, 0.81 or 0.89. These coefficients require the measurements to be in centimeters and milliliters.

2.

Bladder volume = exp (C1+C2 × ln (A1) + C3 × ln (A2))

Where,

A1 = maximal longitudinal cross-section;

A2 = maximal transverse cross-section;

C1 = 0.8304;

C2 = 0.5625; and

C3 = 0.7211.

3.

Bladder volume = height × depth × 0.66 (for a single sagittal scan)

4.

Bladder volume = width x depth x height x correction coefficient

The coefficient value may vary depending on the bladder shape and the method used. Some common values are:

• Unknown: 0.72
• Prolate ellipsoid: 0.52
• Oblate ellipsoid: 0.66
• Sphere: 0.77
• Cylinder: 0.81

5.

Bladder volume = (years of age + 2) × 30 ml (for a children)

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