Free tool
Water Bill Calculator
Enter your monthly water consumption in units (cubic meters) and get an estimated NWSDB bill with a block-by-block breakdown of usage charges plus the monthly service charge. Based on the 2023 NWSDB tariff revision — verify against the current schedule.
Water bill calculator
NWSDB domestic (household) block tariff
| Block | Units | Rate (LKR/m³) | Charge (LKR) |
|---|---|---|---|
| 1–5 m³ | 5 | 80 | 400 |
| 6–10 m³ | 5 | 110 | 550 |
| 11–15 m³ | 5 | 140 | 700 |
| 16–20 m³ | 3 | 170 | 510 |
Usage charge
LKR 2,160
Service charge
LKR 700
Total bill
LKR 2,860
Tariffs as of 2023 NWSDB revision — verify with NWSDB. Excludes sewerage charges and any subsequent tariff revisions.
Frequently asked questions
How is the NWSDB water bill calculated?
Domestic consumption is charged in blocks — the more you use, the higher the per-unit rate in each successive block — plus a monthly service charge that rises with your usage band.
Why did my bill jump when usage barely changed?
Crossing into a higher block raises both the marginal unit rate and often the service charge, so small usage increases near a block boundary can move the bill noticeably.
Does the estimate include sewerage charges?
No — sewerage and other levies are billed separately where applicable. The estimate covers water usage and the service charge only.
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