FOG assumptions
Food service type matters because a sushi counter, coffee shop, full-service restaurant, fried chicken kitchen, and steak-and-seafood restaurant can have different grease characteristics.
Technical Guide
Grease Trap Sizing for Restaurants and Commercial Kitchens
Grease trap sizing is a planning problem before it is an equipment problem. Seats, takeout meals, menu, utensils, fixtures, pump frequency, available space, and jurisdictional review all shape the answer.
How To Think About Size
A useful estimate starts with the business model.
The Genesis calculator asks for seats, turns per seat, takeout meals, food or establishment type, utensil type, and pump frequency. Those inputs help estimate the grease load between pump-outs. The tool then compares the calculated load to listed model capacity and displays a preliminary recommendation.
That is only the beginning. A final design may depend on fixture schedules, plumbing layout, invert elevations, local code, manufacturer requirements, Authority Having Jurisdiction review, available space, traffic rating, service access, and whether one interceptor or multiple devices are appropriate. This page supports the calculator, not a replacement for engineering review.
Key Concepts
The sizing conversation has more than one number.
Meals and turns
Seating capacity alone can be misleading. Turns per seat and takeout meals can change the estimated daily load.
Grease capacity
Capacity relates to how much grease the unit can hold between pump-outs. Pump frequency affects how much accumulation the system must tolerate.
Flow rate
Flow rating is a separate equipment issue from grease storage. It can matter when fixtures, dishwashing, or simultaneous discharge are reviewed.
Maintenance access
A theoretically correct unit can become a bad operational choice if pump access, covers, risers, or traffic conditions make maintenance difficult.
Jurisdictional review
Local authorities, designers, manufacturers, and inspectors may require information that goes beyond a web calculator.
Before You Choose A Model
Ask what could change the recommendation in the field.
- Will the kitchen add a dishwasher, prep sink, fryer, wok, bakery equipment, or expanded takeout line?
- Is the interceptor outside, inside, under slab, under asphalt, or in a traffic-rated area?
- Can pump trucks reach the covers without blocking customers, deliveries, emergency access, or neighboring tenants?
- Are multiple food service users sharing one system?
- Are there existing records for pipe elevations and fixture connections?
- Has an agency, landlord, or design professional already commented on sizing?
Input Quality
The calculator is only as useful as the assumptions entered.
Owners should avoid entering the smallest possible version of the business just to obtain a smaller result. A practical sizing discussion should reflect the likely menu, seating turnover, takeout volume, utensil type, pump frequency, and fixture demand. If the restaurant may expand hours, add a dish machine, change from coffee service to cooking, or add catering, those plans should be disclosed before the project team relies on a preliminary recommendation.
Capacity and flow rate should also be kept separate in the conversation. Grease capacity relates to storage between pump-outs, while flow rate relates to how wastewater moves through the device. A field review can reveal constraints that a calculator cannot see, including pipe elevations, tank depth, service access, traffic loading, and whether multiple interceptors or a different configuration should be reviewed by the design team.
Primary Tool
Run the calculator, then send the report for review.
The calculator captures the operational assumptions and lead attribution fields needed for a measurable follow-up.