A preliminary OSCAR sizing tool — every result traced to the approved design manuals and drawn to scale. The Calculator and Ask OSCAR run on the same verified engine, so the number you size here and the answer the assistant gives stay locked to the same source of truth.
WA · OR · ID · AZ Verified to the design manualsOne verified engine ∞
Enter your pipe run length and elevation rise, and OSCAR calculates the Total Dynamic Head (TDH) for pump selection. Leave blank if you only need the drainfield size.
ft
ft
Zones · auto-sized from Design Flow
One zone by default. Above the per-zone cap (1,500 gpd on XO2) the field auto-splits into equal zones. Change a zone's gpd or its coils and the other updates. The total turns red if zone coils drop below what the design flow needs. Pump is sized off the largest zone.
Green = do somethingTeal = your system, drawn to scalePurple = Ask OSCAR, the AI
Headworks — reverse flush, sized to the number of zones
Preliminary tool for engineers, designers, and regulators. A starting point for a design that a licensed professional reviews and signs — not a final engineered design. Homeowners may use this as a self-service planning aid only.
