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Three Ways to Determine the Right Residential Septic Tank Size

Septic tanks play a critical role in keeping homes without access to public sewage clean and safe, and there are many different options based on the individual or family’s needs. While the type of septic tank can be chosen based on preference, it’s important that the appropriate size be determined carefully so that it can efficiently break down waste. Homeowners can select between a few different methods to help them calculate the septic tank size that works best for their home.

Bedroom and Square Footage Calculation


One of the easiest ways for homeowners to determine the best septic tank size for their home is to choose based on the number of occupied bedrooms in the house and its square footage.

  • One to two bedrooms and less than 1,500 square feet: 750-gallon tank
  • Three bedrooms and less than 2,500 square feet: 1,000-gallon tank
  • Four bedrooms and less than 3,500 square feet: 1,200-gallon tank to 1,250-gallon tank
  • Five to six bedrooms and under 5,500 square feet: 1,500-gallon tank

Water Usage Calculation

Septic professionals consider selecting septic tank size based on daily water usage to be the most accurate method. The average person uses about 75 gallons of water per day, but appliances such as dishwashers and washing machines should be taken into account, as well. Homeowners can check their utility bills for usage specifics.

  • 500 gallons or less: 900-gallon tank
  • 500 to 700 gallons: 1,200-gallon tank
  • 700 to 900 gallons: 1,500-gallon tank
  • 900 to 1,240 gallons: 1,900-gallon tank

Budget-Based Calculation

Those who fall between two different tank sizes based on different calculations may want to consider additional expenses before making a decision. Higher-capacity tanks will cost more upfront, and every type and size of tank will require pumping every three to five years. In these instances, budget may be the deciding factor.

If you need a septic tank, trust the experts at Emerald Coast Wastewater Solutions. We’ve been providing the Destin, FL area with reliable septic tank services for over two decades. Contact us today at (850) 842-4486 for your free septic tank installation estimate.

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