Urinary bladder volume calculator (ultrasound)

Note to first time users: this calculator returns bladder volumes with different correction coefficients depending on the bladder shape. Please go through the detailed notes below if unfamiliar with its assessment.

Notes

• This calculator uses the following formula:
  • Bladder volume = width x depth x height x correction coefficient
• The bladder should be measured in three dimensions in the transverse and longitudinal planes

• The correction factor is depending on the bladder shape:
  • Unknown: 0.72 – most widely used
  • Prolate ellipsoid: 0.52
  • Triangular prism: 0.66
  • Ellipsoid: 0.81
  • Cuboid: 0.89
• The bladder shape can be “eyeballed” but if hard to characterize the 0.72 correction factor is a reasonable choice. Here are some schematic drawings of various common bladder shapes:

• ^{Bih LI, Ho CC, Tsai SJ, Lai YC, Chow W. Bladder shape impact on the accuracy of ultrasonic estimation of bladder volume. Arch Phys Med Rehabil. 1998 Dec;79(12):1553-6. doi: 10.1016/s0003-9993(98)90419-1. PMID: 9862299.}

Last updated: 2021-09-15