Water bill calculator for any slab tariff
This water bill calculator turns your meter readings — or the kilolitres on your bill, or an estimate from the number of people at home — into a water and sewer bill using your own utility’s tariff. Enter the slabs, the rate per kilolitre in each, the service charge, the sewer charge rule and any free-water allowance, and it shows the bill line by line, the cost per 1,000 litres and how many litres each person used per day.
Water tariffs are set by city water boards and revised often, so the calculator does not pretend to know them: the slab table starts with plain example numbers for you to replace. That makes it work for a Delhi Jal Board, Bengaluru (BWSSB) or Hyderabad (HMWSSB) bill, a municipal bill anywhere else, or a US bill in thousand gallons or hundred cubic feet.
How to use the Water Bill Calculator
- Choose how you know your use: Meter readings (previous and current), Units used from the bill, or Estimate from household.
- Pick the meter unit — kL (m³), thousand US gallons or HCF — and enter the people and the days in the billing period.
- Copy the slab limits, rates and service charges from your bill or the board’s tariff notice; add or remove slabs as needed.
- Choose whether slabs are telescopic or apply to the whole consumption, then enter the sewer charge, any free allowance, meter rent and tax.
- Read the total and the working, and copy the summary to check against the bill.
Water Bill Calculator features
Editable slab tariff
Any number of slabs with a rate per unit and a service charge each; the last slab is “and above”.
Two slab methods
Telescopic (each slab’s units at that slab’s rate) or all units at the rate of the slab your consumption reaches.
Sewer and free water
Sewer as a percentage of the water charge and/or a rate per unit; a free allowance that either waives the bill up to a limit or makes the first units free.
Meter readings and estimates
Consumption from two readings, from the bill, or people × litres per person per day × days.
Per-person and per-1,000-litre figures
Compare your daily use per head with planning norms and see what water really costs you.
How a slab water bill is calculated
With the example tariff (₹5 per kL up to 10 kL, ₹10 up to 20, ₹20 up to 30 and ₹30 above; service charges ₹50/100/150/200) and readings of 1,250 and 1,272 kL, the home used 22 kL (22,000 litres).
- If the tariff instead charges all units at the rate of the slab reached, the water charge is 22 × ₹20 = ₹440 and the bill ₹854 — check the wording of your tariff, because the difference is large.
- Telescopic water charge: 10 × ₹5 + 10 × ₹10 + 2 × ₹20 = ₹190.
- Service charge for the 20–30 kL slab: ₹150.
- Sewer charge at 60 % of the water charge: ₹114.
- Total: ₹190 + ₹150 + ₹114 = ₹454, or about ₹20.6 per 1,000 litres.
Tariff structures you will meet
The 2009 Delhi notification is quoted only to show the structure; its rates have since been revised, so take every number from your current bill.
| Feature | How to enter it |
|---|---|
| Service charge that depends on the slab | Service charge column of each slab |
| Sewer charge as a share of the water charge | Sewer charge % (for example, the Delhi Jal Board tariff notified on 16 December 2009 used 60 %) |
| Free water if use stays under a limit | Free water allowance → Bill waived if use is within the limit |
| A fixed number of free units for everyone | Free water allowance → First units always free |
| Minimum charge or meter rent | Meter rent / other |
How much water does a home use?
India’s planning norm in the CPHEEO Manual on Water Supply and Treatment is 135 litres per person per day for towns with a sewerage system and 150 for metropolitan cities. A family of four at 135 litres uses 16.2 kL in 30 days. Leaks are the usual reason for a sudden jump — read the meter at night and in the morning with every tap closed.
Rainwater can cut the bill: the rainwater harvesting calculator estimates what your roof collects. For the other utility bill, see the electricity bill calculator, and split a shared bill with the split bill calculator.
Water Bill Calculator FAQ
How is a water bill calculated?
Consumption = current meter reading − previous reading. The water charge comes from the tariff slabs, then the service charge, sewer charge, meter rent and tax are added. The water bill calculator shows each line.
How do I calculate my Delhi Jal Board, BWSSB or HMWSSB water bill?
Take the slab limits, rates, service charges and sewer rule printed on your bill or in the board’s current tariff notice, type them into the slab table, and enter your readings. The calculator does not store city tariffs because they change.
How many litres is 1 kL of water?
One kilolitre is 1,000 litres, which is also one cubic metre (m³). A US thousand gallons is 3,785 litres and one HCF (100 cubic feet) is 2,832 litres.
What is a telescopic water tariff?
Each slab’s units are charged at that slab’s rate, so crossing into a higher slab only raises the price of the units above the limit. Some tariffs instead charge every unit at the rate of the slab reached.
Why is my water bill so high?
Usually a leak, a tank overflow, or crossing into a higher slab. Compare your litres per person per day with the 135-litre norm and check for leaks.