What size septic tank do you need in Florida?

Florida’s Rule 62-6.008 sets the minimum from your bedrooms or building area, whichever gives the larger flow. A home with up to 3 bedrooms and 2,250 square feet needs a 900-gallon tank. Four bedrooms need 1,050 gallons, five need 1,200 and six need 1,350. HomeAdvisor’s June 2026 guide prices a 1,000-gallon tank at $900 to $1,500.

That number is the state’s floor. On a septic tank installation in South Florida, the county health department checks your floor plan before permitting a tank. The soil then sets the drain field.

What does Florida’s septic tank size chart say?

Florida’s chart lives in Rule 62-6.008. Table I gives each home a daily sewage flow. Table II turns that flow into a minimum tank. Up to 300 gallons a day, the floor is 900 gallons. Each bedroom past four, or each 750 square feet or part of it past 3,300, adds 60 gallons a day.

Rows 5 and 6 apply that 60-gallon step.

The rule assumes at most two people per bedroom. Tanks need multiple chambers or must sit in series, with one exception. An approved outlet filter is required. Even with a separate graywater system, the tank for toilet and kitchen waste holds at least 900 gallons. Shared tanks add 75 gallons per dwelling unit.

How do you work out your own number?

You need two numbers from your house: the bedroom count and the building area. Look each one up in Table I and take whichever gives the larger daily flow. Then read the tank size from Table II. The county health department works from the floor plan in your permit application.

1. Count bedrooms the way Florida law does. A bedroom can be used for sleeping. In a site-built home it has at least 70 square feet of conditioned space. It sits on an exterior wall and has a closet, a door or doorway and an escape opening. Dens and family rooms never count.
2. Measure the building area. Count the enclosed living space from the outside building dimensions, every story included. Leave out the garage, carport, exterior storage shed and open or screened patios or decks.
3. Take the larger flow. If bedrooms and square footage land in different rows, the bigger flow wins.
4. Read the tank row in the chart above.

Take a 3-bedroom home with 2,600 square feet. By bedrooms it rates 300 gallons a day. By area it lands in the 2,251 to 3,300 row, which is 400 gallons a day. The larger flow applies, so the minimum tank is 1,050 gallons instead of 900.

Is a 500 or 750 gallon septic tank big enough in Florida?

Not for a new Florida system. HomeAdvisor’s national chart lists a 500-gallon tank for 1 bedroom and a 750-gallon tank for 2. Both rows sit below Florida’s 900-gallon minimum, so neither meets Rule 62-6.008 for a new home system. The floor holds even for a 1-bedroom home at 100 gallons a day.

The chart’s labels drift higher up, too. HomeAdvisor tags a 1,000-gallon tank for 3 to 4 bedrooms, but in Florida a fourth bedroom calls for 1,050. Its 1,200-gallon row says 5 to 6 bedrooms, while Florida asks 1,350 for six.

How much does each septic tank size cost?

HomeAdvisor’s June 2026 guide prices tanks by size, from $500 for the smallest to $2,500 for a 1,500-gallon tank. A new Florida home system starts at 900 gallons. That leaves the 1,000, 1,200 and 1,500 gallon rows. A full professionally installed system runs $3,590 to $12,463.

These are national market ranges. Our Florida septic tank installation cost guide covers the rest of a new system. A real number for your property needs a site visit and a free quote.

How big does the drain field need to be?

Rule 62-6.008(5) sizes the drain field from the same daily flow, divided by the soil’s loading rate in Table III. Flows under 200 gallons a day are sized as 200. Sandy soil takes more water per square foot, so it needs less area. Clay, organic soils, hardpan and bedrock are rated unsatisfactory for a standard system.

The Table III rates, in gallons per square foot per day:

• Sand and coarse sand: 0.80 in a trench, 0.60 in a bed.
• Fine sandy loams and similar soils: 0.65 in a trench, 0.35 in a bed.
• Coarse sand or oolitic limestone with a high water table: also unsatisfactory.

For the 3-bedroom home at 300 gallons a day in sand, that means 375 square feet of trench. As a bed, it needs 500 square feet. A 4-bedroom home at 400 gallons a day needs 500 square feet of trench.

Broward’s site plan checklist draws a proposed standard tank at a minimum of 5 by 10 feet. The field is drawn at a minimum of 300 square feet. The site evaluation then sets the seasonal high water table and loading rate. The real field may come out smaller or larger. That permitted size is what a drain field installation builds to.

Who decides the size for a South Florida home?

The county health department does, from your permit application. FDEP itself permits septic systems only in Northwest Florida and Marion County. Everywhere else, including Broward, Palm Beach and Miami-Dade, the application goes to the local county health department. A site plan and a building floor plan go with it.

In Broward, the residential floor plan must show the number of bedrooms and the square footage of the building area. Those are the two inputs to Table I.

One more rule applies to new systems. Since July 1, 2023, HB 1379 requires a nitrogen-reducing system on lots of one acre or less inside impacted areas. Our guide to septic permit rules in Broward and Palm Beach covers how to check a lot.

What if you add a bedroom later?

Get the system reapproved before the work starts. Rule 62-6.001(4) says alterations that increase sewage flow require you to apply for and receive reapproval of the system first. The flow is recalculated from bedrooms and building area, with the house and the addition counted together.

Every tank is pumped by a permitted septage disposal service and inspected empty for defects or leaks. A system approved in good shape in the past five years skips the new inspection, unless it has a record of failure.

If the addition raises the flow, the system must meet the current rules in full. The addition may not cover any part of the system. A 3-bedroom home on 900 gallons that adds a fourth bedroom moves into the 1,050-gallon row. Our septic inspection cost guide covers that step and its cost.

What changes the number

• Building area. A big home with few bedrooms can land in a higher row.
• What counts as a bedroom. An office that meets the bedroom tests counts; a den never does.
• Shared tanks. Each dwelling unit on one tank adds 75 gallons.

Tank size also carries into upkeep. Our septic tank pumping cost guide lists pump-out prices by tank size.

Get a size and a price for your property

Planning a new or replacement septic tank? Tell us the bedroom count, the building area and the city when you call. A real number needs a site visit, and the quote is free. We are a licensed septic tank and drain field installation specialist based in Pembroke Pines. Call (954) 350-2046 any hour, or use the contact page. For a tank that only needs emptying, septic tank pumping runs 24 hours a day, 7 days a week.