🚽 Septic Tank Calculator PRO
Estimate septic tank size, drain field area, pipe length, and total installation cost.
Dimension Diagram — updates as you type
Two-chamber tank section. Bedroom count sets the code minimum; daily load sets the working size.
1 Property Details
Code standard: 150 gal per bedroom. Typical usage: 50-100 gal/person/day.
2 Tank Configuration
Results
Tank Sizing (Code-Based)
Tank Dimensions
Drain Field
Cost Breakdown
⚠️ Pre-Export Checklist
- Local health department requirements confirmed
- Percolation test completed by certified tester
- Soil type verified with on-site evaluation
- Setback distances from property line/well verified
- Groundwater level assessed
- Building permit application prepared
- Contractor bids obtained (minimum 3)
Professional Septic Sizing Guide
📐 Formulas & Code Standards ▼
Tank Sizing (IRC/IPC Standard)
Minimum Tank = Bedrooms × 150 gallons
Actual Tank = Max(Code Minimum, Daily Usage × 2-day retention)
Code requires minimum 2-day retention time. Tank must handle peak daily flow.
Drain Field
Absorption Area = Tank Size ÷ 2 (sqft per bedroom)
Adjustment: Clay = ×2, Loam = ×1, Sandy = ×0.75
Soil percolation rate determines field size. Clay soils need significantly more area.
💡 Pro Tips ▼
- Pump every 3-5 years to prevent solids from entering drain field.
- Avoid planting trees near drain field — root intrusion is a leading cause of failure.
- Water conservation reduces system load and extends drain field life.
- Keep records of maintenance, pumping, and inspections for property resale.
- Alternative systems (mound, aerobic) may be required in high water table areas.
Drag to rotate — Scroll to zoom
Calculadoras Relacionadas
Frequently used together on the same project.
Client & Quote (prints on PDF & Excel)
Adjustments (applies to exports)
Contingency is added as a separate line on the exported cost summary. Waste % is printed as an advisory reminder.
Project notes (prints on PDF & Excel)
Result compare (A/B)
| Item | Pinned | Current | Change |
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Saved rates auto-apply from your Price Library. Advanced details stay in your browser — nothing is uploaded except inside your own PDF/Excel exports.
📖 Como Usar a Calculadora
Insira o número de quartos.
Selecione a taxa de percolação do solo.
Escolha o material do tanque.
Insira os custos locais.
Clique em Calcular.
Revise os detalhes.
📐 Fórmulas de Projeto Séptico
⚠️ Erros Comuns de Projeto
Instalar tanque pequeno demais.
Não considerar adições futuras.
Colocar campo perto demais.
Ignorar resultados de testes de solo.
Omitir licenças e inspeções.
💡 Dicas Profissionais
Realize testes de solo antes do projeto.
Considere medidas de economia de água.
Use contratados licenciados.
Instale acessos de acesso.
Mantenha registros detalhados.
Não plante árbores sobre o campo.
Inspecione anualmente e bombeie a cada 3-5 anos.
❓ Perguntas Frequentes
A maioria deve ser bombeada a cada 3 a 5 anos. Uma família de quatro tipicamente precisa de bombeamento a cada 3 a 4 anos.
Depende dos quartos. Dois quartos precisam de 750-1.000 galões. Três 1.000. Quatro 1.000-1.500.
Sistemas básicos custam R$15.000-R$40.000. Avançados custam R$50.000-R$125.000.
Não, nunca deve construir estruturas sobre o campo de drenagem.
Sinais incluem drenagem lenta, odores, pontos úmidos e grama verde sobre o campo.
🏗️ Instalações Reais
Use nossa calculadora para determinar o tamanho do tanque, campo de drenagem e custos estimados.
✅Method, Sources & Review
Maintained by theBuildingCalc methods desk· Last reviewedSeptember 23, 2026. This calculator implements the standards and references below; every figure can be rechecked against the formulas and worked example on this page.
Results are estimates, not engineering advice. Verify against local codes and licensed professionals for structural, electrical, and gas work. See ourTerms. Spotted an error? Report it— corrections ship with the next review.