Tanque reservatório
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
Diário × dias
About this calculator
This calculator helps determine the required size of a rainwater storage tank to meet the needs of a home, building, or agricultural system. The formula used is Volume = daily consumption × storage days ÷ (% efficiency). It accounts for daily water usage, the number of days water needs to be stored, and the efficiency of the collection system. It is recommended for sustainability projects, potable water savings, and areas with water scarcity.
To use the tool, input the average daily consumption (e.g., 500 liters), the number of storage days (e.g., 30 days), and the system efficiency percentage (e.g., 80% for 80% efficiency). The result shows the minimum tank capacity. Note that factors like evaporation losses, system maintenance, and weather variations may affect actual efficiency.
Common precautions include rounding the result to practical values (e.g., 15,000 liters instead of 14,850 L), allowing extra capacity for atypical situations (e.g., prolonged droughts), and ensuring filters and pumps are used to prevent contamination. The tank size must also fit the available installation space.
Frequently asked questions
How to calculate daily water consumption?
Add usage from all consumption points (e.g., showers, kitchen, laundry) and divide by the number of days data was collected.
Does the usage percentage include losses?
No, the percentage refers to collection system efficiency. Evaporation or maintenance losses should be considered separately.
What to do if the result is too large?
Size the tank based on priorities: choose the highest value between the calculation and the location’s minimum requirements.
Is the result in liters or cubic meters?
The result is provided in liters by default but can be converted to cubic meters by dividing by 1000.