What Size Septic Tank Do You Need?
Free calculator based on your state's code requirements. Get instant recommendations for tank size, drainfield, and costs.
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Septic Tank Calculator
Get personalized recommendations based on your state's requirements
How It Works
Get accurate septic tank recommendations in minutes. No signup required.
Enter Your Details
Select your state and enter basic home information like bedrooms and special fixtures.
Get Recommendations
Receive personalized tank size and drainfield recommendations based on your state codes.
Understand Requirements
Learn about permits, professional requirements, and regulatory contacts for your area.
Plan Your Project
Use cost estimates and specifications to plan your septic system installation.
Why Tank Size Matters
Choosing the right septic tank size is crucial for system longevity and proper wastewater treatment.
Frequent Problems
Undersized tanks lead to frequent pumping, system backups, and premature drainfield failure. Solids may enter the drainfield before proper settling.
Optimal Performance
Properly sized tanks provide adequate retention time for solids to settle, protect the drainfield, and require pumping only every 3-5 years.
Unnecessary Cost
Oversized tanks cost more to purchase and install without significant benefits. They may also have longer settling times that could affect bacterial activity.
Find Your State's Requirements
Click on your state for detailed septic regulations and requirements.
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Frequently Asked Questions
Common questions about septic tank sizing and requirements.
What size septic tank do I need for a 3 bedroom house?
Most states require a minimum 1,000-gallon tank for a 3-bedroom home. If you have a garbage disposal, many states require a 50% larger tank (1,500 gallons). Use our calculator above for your exact state requirements.
How often should I pump my septic tank?
The general recommendation is every 3-5 years, but this depends on tank size, household size, and water usage. Our calculator provides a personalized pumping schedule based on your inputs.
What affects drainfield size?
Drainfield size is primarily determined by daily wastewater flow and soil type. Clay soils require larger drainfields due to slower absorption, while sandy soils can use smaller areas.
Do I need a permit for septic installation?
Yes, permits are required in all 50 states for new septic system installations. Our calculator shows the regulatory agency for your state so you can get started on the permit process.
Ready to Calculate Your Septic Size?
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