How each figure is calculated
- Voids per 24 hours — every void counted, day and night. Typical: 4–8.
- Average voided volume — total output ÷ number of voids. Typical: 250–400 ml.
- Maximum voided volume — the largest single void, an estimate of functional bladder capacity. Typical: 400–600 ml.
- Total 24-hour output — all voided volumes added. Typical: 1,200–2,000 ml; above ~40 ml per kg of body weight is termed polyuria.
- Night-time share — night-time volume (including the first void after waking) ÷ total output. Above ~20% (~33% over 65) is described as nocturnal polyuria.
- Intake–output gap — drinks minus output. Normally 500–800 ml leaves the body through breathing, skin and stool.
What the combinations mean — small volumes with high frequency, normal days with heavy nights, and the rest — is covered in how to interpret a bladder diary. If you still need to collect the numbers, see how to measure urine volume at home and a worked bladder diary example.