Good plumbing projects start with the right numbers — the correct pipe diameter, the right fitting for the transition, a realistic budget before anyone picks up a saw. This section collects our reference tools in one place: sizing charts, fitting guides and planning aids you can use on your phone in the store aisle.
ABS pipe sizing quick reference
Drain pipe is sized by the fixture it serves, not by guesswork. The table below covers the sizes you will actually encounter in a home. For outside diameters, wall thicknesses and the full dimension tables, browse our pipe guides library — the complete ABS sizing chart is coming as a dedicated guide.
| Nominal size | Typical home use |
|---|---|
| 1-1/2 inch | Bathroom sink, tub and shower drains; kitchen sink branch lines |
| 2 inch | Shower drains, washing machine standpipes, small branch drains |
| 3 inch | Toilet drains, main branch lines serving a bathroom group |
| 4 inch | Main building drain and building sewer lines |
What is coming
We are building interactive calculators for this section: a repipe cost estimator (enter home size and material for a ballpark range), a drain pipe sizing helper based on fixture units, and a project materials checklist generator. Each tool will be free, work offline once loaded, and never require an account. Until they launch, the guides linked throughout this site cover the same ground in text form — start with plumbing cost guides for budgeting and pipe guides for sizing.
A note on accuracy
Reference tables here follow common US residential practice under the major model codes, but local amendments vary. For permitted work, confirm sizing with your local code or inspector — a two-minute call beats a failed inspection every time.