One of the most common mistakes buyers make isn’t picking the wrong material — it’s picking the wrong size. An undersized tank means running out of water and refilling constantly; an oversized one means paying more upfront and stored water sitting longer than it needs to. Here’s how to actually work it out.
Start With Daily Consumption
A commonly used estimate is 135–150 litres of water per person, per day, for typical Indian household use (drinking, cooking, bathing, cleaning). Multiply that by the number of people in your household, and you have a baseline daily requirement.
For example, a family of 5 at 150 litres/person/day needs roughly 750 litres of water per day.
Decide How Many Days of Backup You Want
Tank sizing isn’t just about one day’s use — it’s about buffer against irregular water supply, which is common in many parts of India. A reasonable approach:
- 1–2 days’ backup: Areas with reliable, consistent municipal supply.
- 3–5 days’ backup: Areas with irregular or scheduled water supply.
For the family of 5 above, 2 days’ backup at 750 litres/day means you’d want a tank in the 1,500-litre range at minimum.
Common Household Sizes
- 500 litres: Small households (2–3 people) with reliable water supply.
- 1,000 litres: Mid-sized families or households wanting a day or two of buffer.
- 1,500–2,000 litres: Larger families, or homes in areas with irregular supply.
- 5,000 litres and above: Apartment buildings, commercial establishments, or industrial use.
Don’t Forget Peak Demand and Future Needs
If you’re planning renovations, an additional floor, or expect your household to grow, it’s worth sizing slightly above your current need rather than needing to add a second tank later. Similarly, commercial and industrial buyers should account for peak usage hours rather than just an average daily figure.
When in Doubt, Ask
Tank sizing isn’t an exact science — it depends on your household size, supply reliability, roof/space constraints, and future plans. A good manufacturer will walk through these factors with you rather than just selling you the most popular size. If you’re unsure, share your household size and supply pattern with our team and we’ll help you land on the right capacity.