How do you measure urine output in diapers?

• A. Subtract the weight of the diaper when dry from its weight when wet
• B. Subtract the weight of the diaper when wet from its weight when dry
• C. Multiply the weight by the fluid density
• D. Add the weights of multiple diapers together

Answer: (A)

Measuring urine output in a diaper is done by weighing the diaper before use and after it becomes wet. Subtract the dry weight from the wet weight; the difference represents the urine volume in milliliters because urine density is about 1 g/mL, so the weight change directly translates to volume. If stool is present, you’d separate it or estimate the urine portion to avoid inflating the reading. This method directly yields the urine output, whereas reversing the subtraction, multiplying by density, or summing diaper weights would not provide the actual urine volume.