Prepared by GreaseTrapLocator · Fact review: August 9, 2026
A gallon label describes liquid capacity for a named product. It does not, by itself, select a grease interceptor for a restaurant or other food-service project. Manufacturer records list liquid capacity as one product field, while local programs can require project approval before purchase. [2][3][4]
Keep the measurements separate
Equipment documents can list more than one measurement. Toronto’s guidance says a point-of-source interceptor label can show flow rating, removal efficiency, maximum containment capacity, and inlet size. For a named product example, Schier lists a 35-GPM flow rating, 130-pound grease capacity, and 20-gallon liquid capacity for its GB2-C model. Those are different fields, and the GB2-C figures apply only to that named model. [1][2]
Do not convert gallons into GPM, grease-retention pounds, fixture units, or retention time. Do not use seats, meals, cuisine, or restaurant type as a substitute for local review. This is a boundary drawn from separately labelled local and named-model records, not a universal sizing formula. [1][2][3]
A math check is not a sizing method
The expression 100 GPM × 30 minutes equals 3,000 gallons. It does not equal 750 gallons, and adding a multiplier cannot make that multiplication smaller. This arithmetic was independently recalculated; it is not a sizing method. A local program may use a different method and different inputs.
For example, Austin Water publishes its own local process: it calculates a flow rating from connected fixture units and then calculates local minimum liquid holding capacity from that flow rating. Austin also tells applicants not to purchase a grease trap or interceptor before building-plan approval and an Industrial Waste approval letter that specifies the required size and design. Those requirements apply in Austin, Texas only. [3]
Use the local approval process
Toronto requires a building permit to install or replace a grease interceptor in its program. Austin uses an Industrial Waste approval letter before purchase. These two examples show why a local authority, rather than a generic national chart, should define the approval path for a project. [1][3]
Before a capacity proposal is reviewed, ask the local authority or project team which fixtures are included, which current product documents are required, and which local calculation or approval process applies. This page does not provide a calculator, a restaurant-type table, or installation instructions.
Read a product document without turning it into a shortcut
Schier’s GB-1000 page lists a 1,000-gallon liquid-capacity configuration and 100- and 200-GPM configurations for that named product line. Those values do not mean that 1,000 gallons is a standard restaurant size or that the GPM figures can be converted into a required capacity. Product ratings must be read alongside the local approval process and the documents for the exact proposed configuration. [4]
Frequently asked questions
Does a gallon label tell me what size interceptor to buy?
No. A gallon label is one equipment measurement. Local approval and the approved design determine the requirements for a specific project. [1][3]
Is 100 GPM times 30 minutes equal to 750 gallons?
No. 100 GPM multiplied by 30 minutes equals 3,000 gallons. That calculation corrects the arithmetic only; it is not a generic sizing method.
Are GPM, liquid gallons, and grease capacity the same thing?
No. Toronto identifies separate label fields, and Schier’s GB2-C publishes separate 35-GPM, 130-pound, and 20-gallon values for that named model. They should not be converted into one another. [1][2]
Can seats, meals, or cuisine choose an interceptor size?
No. This page does not use seats, meals, cuisine, or restaurant type as a sizing shortcut. Use the locally applicable approval process and approved project design. [1][3]
What should I take to local review?
Ask the local authority what it requires for the site, the connected fixtures, and the exact proposed product. Austin’s approval-before-purchase process and Toronto’s permit process are local examples, not universal checklists. [1][3]
Sources
- City of Toronto, “Grease Interceptor Installation” (modified May 14, 2026; accessed August 9, 2026). Toronto/Ontario only.
- Schier Products, “GB2-C Grease Interceptor” (accessed August 9, 2026). Named GB2-C model only.
- Austin Water, “Grease Trap Sizing & Design Criteria” (accessed August 9, 2026; policy updated April 2021). Austin, Texas only.
- Schier Products, “GB-1000 Grease Interceptor” (accessed August 9, 2026). Named product line only.
Author: Grease Trap Locator Editorial Team
The Grease Trap Locator editorial team covers FOG compliance, grease trap maintenance, and commercial kitchen regulations across the US and Canada. Our guides are written for restaurant owners, facility managers, and food service operators who need practical, accurate information without the fluff.
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