Calculadora de Conta de Água
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
conta = taxa_fixa + m³ × tarifa
About this calculator
The Water Bill Calculator is a practical tool to estimate your monthly water bill. It considers consumption in cubic meters (m³) and the rate charged by the local utility, plus a fixed base fee. Simply enter your consumption and the rate per m³ to get a quick forecast of the total amount due.
The calculation is straightforward: add the fixed fee (minimum amount charged regardless of consumption) to the product of consumption in m³ and the rate per m³. For example, if the fixed fee is R$ 30.00, the rate is R$ 5.00/m³ and you consumed 15 m³, the bill will be R$ 30.00 + (15 × R$ 5.00) = R$ 105.00. This basic formula is common in many regions, but rates may vary by consumption tier.
Use this calculator to plan your household budget, compare bills from different months, or simulate the impact of reducing consumption. It is useful for families, tenants, and homeowners who want to better understand their water expenses. Remember that rates can be progressive: the more you consume, the higher the price per m³.
Caution: this calculator provides an estimate, not a substitute for the official bill. Check your actual bill for additional charges such as sewage, taxes, or tariff flags. Also, the fixed fee may vary by connection type (residential, commercial) and city. Always consult your utility's rate table.
Frequently asked questions
How do I find out the water rate in my city?
Check your local water utility's website or your latest bill, where the rate per m³ and the fixed fee are listed.
Does the calculator consider progressive rates (by consumption tiers)?
No, this calculator uses a single rate per m³. For progressive rates, you need to calculate each tier separately and add up the amounts.
What is included in the fixed fee?
The fixed fee covers administrative and network maintenance costs, regardless of consumption. The amount varies by utility and connection type.
Why is my actual bill different from the calculated value?
The actual bill may include extra charges like sewage, taxes (e.g., ICMS), and tariff flags. The calculator only considers fixed fee and consumption.
Can I use this calculator for commercial consumption?
Yes, but adjust the fixed fee and rate according to your utility's commercial table, as values are usually different from residential ones.