Printable chart
Septic tank size chart — by state
Minimum tank size by bedroom count, from each state's own rule. This is the chart to print: unlike the single national table most sites copy around, every row below is a different state's actual requirement — which is why the rows don't match each other.
Read it as a comparison, not a lookup table: Texas and Florida need extra inputs (living area, water-saving devices) that a chart row can only summarize, and Michigan's numbers are set county by county. Your state's page — linked from its row — runs the full rule.
3-bedroom minimums, compared
The full chart (gallons)
| State | 1 bed | 2 bed | 3 bed | 4 bed | 5 bed | 6 bed |
|---|---|---|---|---|---|---|
| Texas — sized from wastewater flow (range: with / without water-saving devices) | 750 | 750 | 750–1,000 | 1,000–1,250 | 1,250 | 1,250–1,500 |
| Florida — by bedrooms × living area | 900–1,350 | 900–1,350 | 900–1,350 | 1,050–1,200 | 1,200 | 1,350 |
| North Carolina | 1,000 | 1,000 | 1,000 | 1,000 | 1,250 | 1,500 |
| Ohio | 1,000 | 1,000 | 1,500 | 2,000 | 2,000 | 2,500 |
| New York | 1,000 | 1,000 | 1,000 | 1,250 | 1,500 | 1,750 |
| Pennsylvania | 900 | 900 | 900 | 1,250 | 1,400 | 1,550 |
| Virginia | 750 | 750 | 900 | 1,200 | 1,500 | by formula |
| Georgia | 1,000 | 1,000 | 1,000 | 1,000 | 1,250 | 1,500 |
| Missouri | 1,000 | 1,000 | 1,000 | 1,250 | 1,500 | by formula |
| Michigan — set by county* | 750 | 750 | 1,000 | 1,250 | 1,500* | 1,750* |
*Michigan sets sizes county by county; the row shows one real district's table (Central Michigan District Health Department, six counties) including its "+250 gal per extra bedroom" rule — your county's numbers will differ. Florida rows show the range across its living-area bands; the Florida page has the full two-way table. Missouri 6-bedroom and Pennsylvania rows are worked from each code's formula. Every figure: state rule citation on the state page, checked Nov 10, 2026.
Read your state's row properly
A chart row is the state floor for a standard home. Three things can push your real requirement up: a garbage disposal (each state treats it differently — the calculator applies your state's own rule), a county rule stricter than the state's, and a large living area in Florida. When in doubt, the state page for your state shows the rule text summary and links the official source.
Chart questions
How many bedrooms will a 1,000-gallon septic tank support?
In most of our checked states, three: Florida (smaller homes), Georgia, Missouri, North Carolina, New York and the example Michigan county district all land a 3-bedroom home at 1,000 gallons or under. Ohio is the exception in our first ten — its 1,000-gallon row only covers 1–2 bedrooms.
What is the standard septic tank size for a 3-bedroom house?
There is no single national standard — that is the point of this chart. Across the ten states we have checked from official sources, the 3-bedroom minimum runs from 900 gallons (Virginia; Florida homes up to 2,250 sq ft) to 1,500 gallons (Ohio). 1,000 gallons is the most common answer, not a universal one.
How big of a septic tank do I need?
Start with bedrooms, then check your state — the same house legitimately needs different tanks in different states. For a 3-bedroom home the verified minimums in our ten states run 900 to 1,500 gallons; for 4 bedrooms, 1,000 to 2,000. Read your state's row in the chart above, or use the calculator on our home page for the number with its rule citation.
Why does the same house need different tanks in different states?
Because each state picked different math: design flow (Texas), bedrooms plus living area (Florida), a flow formula (Pennsylvania), county codes (Michigan). The geology differs too — states protect their water tables differently.