Calculate minimum pipe diameter in seconds. The DFU Pipe Sizing Calculator lets you tap to add fixtures — water closets, lavatories, showers, tubs — and instantly see the minimum drain pipe size per IPC Table 710.1.
This is the tool you'll keep using after you pass the exam.
500+ PRACTICE QUESTIONS
Covering drainage systems, DFU calculations, venting requirements, trap seals, water supply sizing, backflow prevention, gas piping (IFGC), and storm drainage. Every question includes a detailed explanation referencing the actual code section.
PIPE SIZE REFERENCE
Quick lookup tables for drain pipe sizing by DFU, vent pipe sizing by trap size, water supply sizing, and slope requirements.
STUDY OFFLINE
Every question and tool works without internet. Study on the job site, on the commute, or during downtime.
PROGRESS TRACKING
See your scores by category. Focus on weak areas. Know when you're ready to sit for the exam.
SUBSCRIPTION INFORMATION
Plumber Prep Pro Monthly: $3.99/month
- Unlimited practice questions
- Full pipe sizing calculator
- All reference materials
- Auto-renews monthly
Payment will be charged to your Apple ID account. Subscription automatically renews unless canceled at least 24 hours before the end of the current period. Manage subscriptions in Settings > Apple ID > Subscriptions.
Download now. Pass your plumber licensing exam the first time.