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Water meter calculator
See whether a water meter would cost you less than your current unmetered bill, using the charges printed on your water company’s tariff.
Estimated metered bill per year
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Enter your charges to compare.
- England and Wales
- Last checked 25 October 2026
- Expert review pending
- How we calculate
How this is calculated
Water use per year in cubic metres is people × litres per person per day × 365 ÷ 1,000. One cubic metre is 1,000 litres.
The metered bill is that volume × the water charge, plus 95% of the volume × the sewerage charge, plus standing charges. Most companies assume 95% of the water you use goes back to the sewer, and charge sewerage on that. Check your company’s charges scheme, as some use a different figure or include it in the sewerage rate already.
Charges vary a lot between companies and change every April. We don’t prefill them because a national average would be wrong for most people. Your company’s website lists the exact figures.
Worked example
A couple in a three-bed house
Two people using 142 litres a day each use 2 × 142 × 365 ÷ 1,000 = 103.7 cubic metres a year. At £2.10 for water and £2.40 for sewerage, with £60 of standing charges, the metered bill is £217.69 + £236.34 + £60 = £514.03. Against an unmetered bill of £620, a meter would save about £106 a year.
Questions people ask
Will a water meter save me money?
Often, if fewer people live in the home than there are bedrooms. Unmetered bills are based on the home’s old rateable value, not how much water you use, so a single person or a couple in a larger house usually pays less on a meter. A big family in a small house may pay more.
Can I switch back if a meter costs more?
In England and Wales you can usually switch back to unmetered charges within 24 months of the meter being fitted, or within one month of your second metered bill, whichever is later. You can’t switch back if you have moved into a home that already had a meter.
Is it free to have a water meter fitted?
Yes. Water companies in England and Wales fit a meter free of charge if you ask, unless it isn’t practical, in which case they must offer an assessed charge instead.
How much water does one person use?
Water UK puts average use at about 142 litres per person per day. Your own use could be well above or below that: showers, baths, washing machines and garden watering make the biggest difference.
What about Scotland and Northern Ireland?
Most homes in Scotland pay water and sewerage charges with council tax, based on the council tax band, and domestic customers in Northern Ireland do not currently pay separate water charges. This calculator is for England and Wales.