Bills & Utilities
UK Water Bill Calculator
Choose metered, unmetered, or assessed billing and enter water, sewerage, standing, and fixed charges from your supplier bill or charge sheet.
Inputs
Results
Useful next checks
- Check the inputs before relying on the result.
- Try a second scenario to compare outcomes.
- Read the guide below for context.
# UK Water Bill Calculator
Estimate a UK water bill from metered usage, unmetered rateable value, or an assessed annual charge.
What this calculator does
UK water bills can be metered, unmetered, or assessed when a meter cannot be fitted. This calculator handles all three common structures with water, sewerage, standing charges, and surface drainage style fixed charges.
How it works
For metered bills, the estimate is:
`water m3 x water rate + water standing charge + sewerage m3 x sewerage rate + sewerage standing charge + fixed charges`
For unmetered bills, the estimate is:
`rateable value x water rate + water standing charge + rateable value x sewerage rate + sewerage standing charge + fixed charges`
For assessed bills, enter the assessed annual amount and any extra fixed charges.
Example calculation
If a metered household uses 100 m3 a year, and the combined water and sewerage rates plus standing charges add up to GBP 515, the monthly equivalent is about GBP 42.92.
How to use the result
Use your supplier's charge sheet or bill values. Water and sewerage may be charged by different companies in some areas, so enter only the services included on the bill you are checking.
Assumptions and limitations
Water charging rules and charge levels vary by water company, region, service, drainage status, and billing method. England and Wales commonly use rateable value for older unmetered homes; Scotland and Northern Ireland have different household water billing arrangements.
FAQs
What is rateable value?
Rateable value is an older property valuation used by water companies for some unmetered bills. It is not the same as modern council tax banding.
What is an assessed charge?
An assessed charge can be used when a household asks for a meter but one cannot reasonably be installed. It is usually based on property or occupancy assumptions.
Is metered water always cheaper?
Not always. It often helps smaller households, but the result depends on usage, rateable value, regional rates, sewerage, and fixed charges.
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Frequently asked questions
Can I use this outside England and Wales?
Use caution. England and Wales commonly use metered and rateable-value structures, while Scotland and Northern Ireland have different household water billing systems.
What if water and sewerage are separate bills?
Run the relevant parts separately or set rates for services not on the bill to zero.