Bladder Capacity Calculator

Summary

Calculate expected and functional bladder capacity by age and gender using the Koff formula for children and standard adult urology norms.

How it works

1. Enter the patient's age in years.
2. Select biological sex (affects adult capacity estimates).
3. Optionally enter a measured functional bladder volume in mL or oz.
4. The calculator applies the Koff formula for children under 13 and adult norms for older patients.
5. Results show expected capacity, functional capacity range, and whether a measured volume is within normal limits.

Use cases

• Urologists assessing voiding diary data against age-appropriate norms.
• Pediatric nurses estimating expected bladder capacity before catheterization.
• Parents tracking a child's bladder development and toilet training milestones.
• Patients with overactive bladder comparing their functional capacity to normal ranges.
• Urology students learning to apply the Koff formula and adult capacity formulas.
• Researchers comparing measured volumes from urodynamic studies to reference values.

Frequently Asked Questions