Definition
Direct answer
A plumbing sizing value used to estimate probable drainage or water-supply demand. On the Plumbing License Practice Test, treat Fixture Unit as a concept to understand, not an answer letter to memorize. Review how it affects safety, code interpretation, jobsite decisions, or timed problem solving, then answer a short practice set tied to Trade math, Drainage and venting concepts, Water supply concepts.
How to use this answer
Read the answer once, then prove it by choosing an answer in a practice question before looking at the explanation. If the miss repeats, tag the domain as Glossary and drill a smaller set before returning to mixed practice.
Prep path
Plumbing License Study Guide
Independent plumbing license study guide for drainage, venting, traps, water supply, fixture units, and code review.
SamplesPlumbing License Sample Questions
Public Plumbing License Practice Test sample questions with explanations.
PracticeOpen Plumbing License Practice Test
Start with the 15-question free set before deciding whether to unlock the paid bank.