Interactive Calculator · 2026
Water Reuse Savings Calculator
See the money you save by reusing STP-treated water instead of buying fresh supply. Enter how much treated water you reuse each day, your water cost, and any tanker premium — get the daily, monthly and annual rupees saved.
Rupees saved — per day, per month, per year
Your reuse & water cost
Treated water you reuse for flushing, landscape, cooling, etc.
What fresh water costs you per kilolitre (1 KL = 1,000 L).
Extra cost of tankered water over the base rate — reusing water avoids this too.
Savings across timeframes
At an effective rate of Rs 60 / KL, every kilolitre reused is money not spent on fresh supply.
Reusing STP-treated water for flushing, landscape and cooling directly replaces fresh water you would otherwise buy — often the fastest-paying part of the whole system.
Where fresh water arrives by tanker, the saving is larger still: the tanker premium is avoided on every litre you reuse.
How this is calculated
- Effective rate = water cost × (1 + tanker premium) = 60 × (1 + 0%) = Rs 60 / KL.
- Daily saving = reuse volume × effective rate = 160 × Rs 60 = Rs 9,600.
- Monthly saving = daily × 30 = Rs 2,88,000.
- Annual saving = daily × 365 = Rs 35,04,000 (reusing 58,400 KL a year).
Indicative figures for concept planning. Actual savings depend on tariff slabs, tanker rates and how much treated water you can put to use — confirm with your water bills before budgeting.
Related Guides — Deep-dive reading
ROI of Water Recycling: Does an STP Actually Pay for Itself?
A numerate, honest look at the payback case for on-site sewage treatment in India — what a recycled kilolitre is really worth, what the plant costs to build and run, and how many years it takes to break even.
Sewage Treatment PlantsReducing an STP's Carbon Footprint: The Net-Emissions Guide
An STP burns power around the clock — but the treated water it produces displaces tankered and pumped freshwater. This guide shows how to weigh the two, then shrink the net carbon footprint with efficient aeration, solar and biogas.
Sewage Treatment PlantsSTP for Villas: Do You Need One, and Which Type Fits a Single Home?
When an individual villa actually needs a sewage treatment plant instead of a septic tank, the tiny capacities involved, and how to choose a compact MBBR or extended-aeration package that fits the plot, the budget and the garden.
Sewage Treatment PlantsRelated Tools — You may also find these useful
Water Carbon Savings Calculator
Estimate the CO2 emissions you avoid each year by reusing treated water instead of fresh supply, with annual tonnes saved and a tree-equivalent.
SustainabilityWater Recycling Dashboard
Enter fresh supply, sewage and treated-water reused (KLD) to see your building's reuse percentage plus the money, water and CO₂ saved each year, with live charts.
DashboardRainwater + STP Integration Calculator
Combine rooftop rainwater harvesting with STP treated-water reuse to estimate the total non-potable water your building can supply in KL per year.
Water Calculator