Grease Trap Pumping Calculator

How to Calculate Your Grease Trap Pumping Schedule

This free grease trap pumping calculator helps restaurant owners in Southern California determine how often their grease trap needs cleaning. Enter your trap size in gallons, select your restaurant type, provide your average daily covers, and choose your deep fryer count. The calculator estimates a recommended pumping frequency in weeks and flags whether your current schedule puts you at risk for FOG violations.

The calculation is based on the 25% rule used by most California health departments and regional water boards. When fats, oils, and grease exceed 25% of your trap capacity, you are in violation and risk fines ranging from $200 to $5,000 per incident depending on your jurisdiction. High-volume frying operations with multiple fryers need significantly more frequent pumping than bakeries or cafes with minimal grease output.

What Size Grease Trap Does My Restaurant Need?

Grease trap sizing depends on your kitchen flow rate and local plumbing codes. Most under-sink units range from 20 to 50 gallons and serve small cafes, food trucks, and bakeries. Full-service restaurants typically need 50 to 100-gallon traps. High-volume operations like fast food chains, fried chicken restaurants, and hotel kitchens often require 150 to 200-gallon in-ground interceptors. If you are unsure about your trap size, check the nameplate on the unit or ask your plumber during the next service visit.

How Often Should a Restaurant Pump Its Grease Trap in California?

California does not mandate a single universal pumping frequency — it depends on your trap size, kitchen volume, and what you cook. However, most municipal FOG programs require that you pump before the grease cap exceeds 25% of total trap depth. As a general guideline, small indoor traps need pumping every 30 to 60 days, mid-size restaurant traps every 60 to 90 days, and large outdoor interceptors monthly. Fast food and heavy frying operations should err on the shorter end of that range.

What Happens If You Skip Grease Trap Cleaning?

Skipping scheduled grease trap maintenance creates a cascade of problems. Grease backs up into your kitchen sinks and floor drains, producing foul odors that reach your dining room. FOG entering the municipal sewer system triggers violations from your local water authority. Health inspectors can issue citations, mandatory increased pumping schedules at your expense, or in severe cases shut down food preparation until the issue is resolved. Emergency grease trap service costs two to five times more than scheduled cleaning.