Thames Water Meter Calculator

It depends on how much water you use and on your current unmetered bill, which is based on your property's rateable value. Enter your unmetered bill and your household's usage in our Thames Water meter calculator, which starts from Thames Water's published 2026-27 metered rates.

From 1 April 2026 Thames Water charges £2.7346 per cubic metre for clean water and £1.4721 per cubic metre for wastewater, plus fixed charges of £66.87 (water) and £128.13 (wastewater) a year, according to Thames Water's metered charges page. Water UK puts Thames Water's average 2026-27 household bill at £658, up £3 (0.4%).

Thames Water serves 15 million customers across London and the Thames Valley, including London, Oxford, Reading, Slough, Windsor, Guildford, parts of Surrey, Hertfordshire, Buckinghamshire, Berkshire, and Gloucestershire. It's the UK's largest water company by customer base.

Yes, Thames Water offers a 2-year trial period for water meters. If you're not saving money with a meter, you can switch back to unmetered billing within this period at no charge, provided your property still has an unmetered rateable value.

Yes, Thames Water installs water meters completely free of charge for household customers. Installation typically takes 2-3 hours and doesn't require you to be home. They also offer free water-saving devices to help reduce your Thames Water bills further.

Water UK lists Thames Water's average household bill for 2026-27 at £658, up £3 (0.4%). Thames Water's own FAQ says water and wastewater bills rose by an average of 3.4% for most households, around £2 a month. The two figures are measured on different bases. Your own change depends on whether you have a meter and how much water you use.

Thames Water meters are read automatically in most areas using smart meter technology. For traditional meters, readings are taken every 6 months, and you can submit your own Thames Water meter readings online or via their app to ensure accurate bills.