Septic tank size by state / South Atlantic
Florida septic tank size
In Florida the minimum septic tank for a three-bedroom house is 900 gallons, rising to 1,050 gallons at four bedrooms. The figure comes from Fla. Admin. Code R. 62-6.008(1) Table I (design flow) and 62-6.008(2) Table II (tank capacity), which sizes the tank from design flow; the bedroom figures below are that rule's arithmetic. That is 100 gallons less than the 1,000-gallon median of the 47 states listed here.
What the Florida rule says
The rule is Fla. Admin. Code R. 62-6.008(1) Table I (design flow) and 62-6.008(2) Table II (tank capacity), administered by Florida Department of Environmental Protection (onsite sewage program, transferred from DOH in 2021). In its own words:
Table II ... AVERAGE SEWAGE FLOW GALLONS/DAY | SEPTIC TANK MINIMUM EFFECTIVE CAPACITY: 0-200 | 900; 201-300 | 900; 301-400 | 1,050; 401-500 | 1,200; 501-600 | 1,350. Table I: 3 Bedrooms with 1,201-2,250 square feet of building area: 300
Source: Fla. Admin. Code R. 62-6.008(1) Table I (design flow) and 62-6.008(2) Table II (tank capacity), read 2026-10-20.
- Florida sizes from estimated daily flow, which depends on bedrooms and on building area together.
- A large house can need a bigger tank than its bedroom count suggests: every extra 750 sq ft adds 60 gallons a day of flow.
- Any tank receiving toilet waste must hold at least 900 gallons.
Florida minimum tank size by bedrooms
| Bedrooms | Minimum tank | Versus the median state |
|---|---|---|
| 1 | 900 gal | −100 |
| 2 | 900 gal | — |
| 3 | 900 gal | −100 |
| 4 | 1,050 gal | −150 |
| 5 | 1,200 gal | −300 |
| 6 | 1,350 gal | — |
The first step up comes at 4 bedrooms, from 900 to 1,050 gallons, and a six-bedroom house needs 1,350 gallons. These are minimums: the permit can call for more, and a bigger tank needs pumping less often.
How Florida compares with nearby states
Delaware requires 1,000 gallons for three bedrooms; Georgia requires 1,000 gallons for three bedrooms; Maryland requires 1,000 gallons for three bedrooms; North Carolina requires 1,000 gallons for three bedrooms; South Carolina requires 1,000 gallons for three bedrooms; Virginia requires 900 gallons for three bedrooms; West Virginia requires 1,000 gallons for three bedrooms. 4 of the 47 states listed here share Florida's three-bedroom figure.
Before you size a tank in Florida
- Bedrooms, not people, set the size in most rules. Rooms that could be used as bedrooms are usually counted, so check how your permitting office counts a den or a finished basement.
- Garbage disposals, grinder or ejector pumps and large tubs change the answer in many states; the points above list Florida's adjustments.
- The tank is only half the system. The drainfield is sized separately from soil tests, and it is usually the bigger cost.
- A private well on the same lot has its own setbacks from the tank and field; the well pump and pressure tank calculators size the water side.
Figures are the state's minimum as written on 2026-10-20. Local health departments can require more; the permit issued for your property governs. See the methodology for how each state was read.