Septic Tank Size Calculator
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Septic guides

Six guides,paired to four calculators.

Each guide is paired with a calculator. Read the guide for the concepts; run the calculator to get the number for your specific property.

Tank Sizing

Calculator (the hub)

Septic Tank Size Calculator

Get tank-size recommendations based on bedrooms, fixtures, and your state code.

Companion guides

How Septic Systems WorkCompanion

The foundational guide. What every septic owner should understand before sizing or budgeting.

Septic System Maintenance

Sized right, maintained right. What proper care looks like over a system’s life.

Septic System Costs

How sizing decisions cascade into installation cost. Budget realistically before you buy.

Drainfield

Calculator (the hub)

Drainfield Size Calculator

Calculate the absorption area you need, by soil type and water usage.

Companion guides

Understanding Your DrainfieldCompanion

How drainfields work, the five major types, and how to keep one alive for 25+ years.

Soil Testing & Perc Tests

Soil determines drainfield design. Learn what a perc test measures and how to read the result.

Troubleshooting Septic Problems

Most "septic" problems are really drainfield problems. Spot the warning signs early.

Cost Estimating

Calculator (the hub)

Septic System Cost Estimator

Total install cost (tank, drainfield, permits, and labor) for your bedroom count and soil.

Companion guides

Septic System CostsCompanion

A full cost breakdown: install, ongoing maintenance, common repairs, and where money goes.

How Septic Systems Work

Know what you’re paying for. The four parts of a septic system explained.

Understanding Your Drainfield

The drainfield is the most expensive component. Protect this and you protect the budget.

Pump Schedule

Calculator (the hub)

Pump Schedule Calculator

Personalized pumping interval based on tank size, household, and habits.

Companion guides

Septic System MaintenanceCompanion

The full maintenance playbook: schedule, do’s and don’ts, drainfield protection.

Troubleshooting Septic Problems

Slow drains, odors, soggy yard: the signs your tank is overdue or your field is failing.

How Septic Systems Work

Why pumping every 3–5 years exists as a rule of thumb. The biology behind the schedule.

Some guides serve more than one topic. For example, “How Septic Systems Work” is the foundation for tank sizing and a sibling read for cost estimating.

Recap

Calculator + companion guide, in one place

The grid above gives you the long version. This compact view is the same map at a glance. Pick the calculator that matches your question, then read its companion guide for context.

Tank Sizing

Calculator

Septic Tank Size Calculator

Get tank-size recommendations based on bedrooms, fixtures, and your state code.

Companion guide

How Septic Systems Work

The foundational guide. What every septic owner should understand before sizing or budgeting.

Drainfield

Calculator

Drainfield Size Calculator

Calculate the absorption area you need, by soil type and water usage.

Companion guide

Understanding Your Drainfield

How drainfields work, the five major types, and how to keep one alive for 25+ years.

Cost Estimating

Calculator

Septic System Cost Estimator

Total install cost (tank, drainfield, permits, and labor) for your bedroom count and soil.

Companion guide

Septic System Costs

A full cost breakdown: install, ongoing maintenance, common repairs, and where money goes.

Pump Schedule

Calculator

Pump Schedule Calculator

Personalized pumping interval based on tank size, household, and habits.

Companion guide

Septic System Maintenance

The full maintenance playbook: schedule, do’s and don’ts, drainfield protection.

Septic Tank Size Calculator

Free septic tank sizing calculator covering all 50 US states. Get accurate recommendations based on your state's code requirements.

Tools

Tank Size CalculatorDrainfield CalculatorCost EstimatorPump Schedule

Guides

Septic BasicsDrainfield GuideSeptic CostsMaintenanceSoil TestingTroubleshooting

Resources

State RequirementsArticlesAll GuidesFAQ

Information

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Disclaimer: This calculator provides estimates only and should not be used as the sole basis for septic system design. Always consult with licensed septic professionals and local health department officials before installing or modifying a septic system. Local codes may have stricter requirements than state minimums.

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