Grease Trap Sizing

Volume from peak flow, retention, and loading factor; PDI G101 cited.

Run the calculator

Example

You enter

Peak fixture flow (gpm) 50
Retention time (min) 30
Loading factor 1.25

You get

Required volume 1875 gal
Recommended nominal 2000 gal

Details, formula, and sources

Volume = peak GPM × retention time × loading factor. Recommended nominal sizes follow PDI G101 step ladder. IPC 2021 Section 1003 governs interceptor selection.

PDI G101 by name; IPC 2021 (International Plumbing Code). Section 1003.

Free read-only access at codes.iccsafe.org. PDI G101 licensed; manufacturer (Schier, Thermaco, Rockford) sizing tools free.

Estimate. AHJ and licensed plumber / gas fitter govern. Verify against the IPC / IFGC edition adopted in your jurisdiction.

Field names used by the API: peak_flow_gpm, retention_minutes, loading_factor, volume_gal, recommended_nominal_gal

Retention time 30 min unless user suppliesPDI G101 by name
Loading factor 1.0 unless user supplies adjustment for high-grease useengineering practice