Water Meter Calculator

If you request it, water suppliers in England and Wales must try to install a water meter at your home free of charge. Switching to a metered water supply could save you money, but it could cost you more.

We've built a water meter calculator that precisely calculates how much you could save with a water meter based on the 2024/25 water rates.

Should I request a water meter?

In this article, we aim to offer a definitive answer to whether you should request a water meter.

Here’s what we cover:

Water meter calculator – 2024/25

Our water meter calculator is designed to accurately determine whether you can expect to save money by requesting a water meter.

By entering just a few simple details, you can compare your water bill on an unmetered tariff with what it would be under a metered tariff.


These figures are based on the most common domestic tariffs used by water companies in England and Wales. It is essential to consult your water company’s comprehensive scheme of charges.
The water consumption estimator mentioned calculates the average household water consumption. This is merely an estimate and should not be considered a precise calculation of your home’s water usage.
Your actual consumption will vary depending on factors unique to your household, including the type and usage of appliances and the design of your bathroom fittings.
Each water company offers its own water meter calculator; it is recommended that you consult this tool before requesting a water meter.

The water meter calculator explained

The British water infrastructure is managed by more than 20 separate water companies, each with its own method for charging for metered and unmetered water tariffs.

The calculator utilises the scheme of charges of each supplier to calculate your annual bill, taking into account both consumption and rateable value inputs.

Below is an explanation of how each of these tariffs functions:

Unmetered ratable value water tariffs

For homes without a water meter, water bills are typically calculated by referencing your property’s rateable value.

The Rateable Value, employed for both water bills and council tax bills, is an assessed value of a property used by HM Revenue and Customs (HMRC) until 1990, after which these values ceased to be updated.

The Rateable Value applied to your water bills corresponds to your home’s rateable value as of 1990, which remains fixed at this figure.

You’ll find the rateable value of your home on a recent water bill, and it will look something like this:

Rateable value charges on a water bill

Source: Affinity Water – Your bill explained

The home above has a rateable value of £219, which is then utilised to compute water and wastewater usage charges.

Our calculator uses your rateable value and the relevant scheme of charges in your area to estimate your annual water bill without a water meter.

💡Rateable value ignores the thousands. So £219 means the home was valued at £219,000 in 1990 by HMRC.

Measured water tariffs

Once a water meter is installed, your water supplier will charge based on the amount of water your home actually uses.

Your water company will conduct regular meter readings to determine your water usage. The usage charge on your bill is then calculated by multiplying your water consumption by the volumetric rates for both water and wastewater.

Here’s an example:

Measured charges on a water bill

Source: Affinity Water – Your bill explained

Scotland and Northern Ireland water meter requests

Our water meter calculator is designed exclusively for homes in England and Wales. We have excluded Scotland and Northern Ireland from its scope for the following reasons:

  • Scotland – Water bills are included in a combined service charge, and you cannot request a free meter from Scottish Water.
  • Northern Ireland – You cannot request a free water meter from NI Water.

What are the benefits of water meters?

Our water meter calculator can help determine if you could save money by requesting a water meter. However, there are additional benefits to having a water meter installed:

<h3>Control over water bills</h3>

Control over water bills

A water meter gives you control over your water bill, as you will only be charged for the water you consume. By reducing your water footprint, you can contribute to environmental conservation and decrease your water expenditure.

<h3>Environmental benefits</h3>

Environmental benefits

Installing a water meter promotes water conservation, reducing the energy required for treating and transporting water to your home. This can lower your household’s carbon footprint and assist your local water company in managing water scarcity more effectively.

<h3>Two-year lowest bill guarantee</h3>

Two-year lowest bill guarantee

The majority of water companies offer a guarantee that opting for a water meter will not result in higher bills for a period of two years. Should you discover that your bills have indeed risen during this time, you will be provided the option to switch back to an unmeasured tariff.

What are the problems with a water meter?

While water meters can offer savings and environmental benefits, there are reasons why some homeowners might hesitate to request one. Here are a few issues to consider:

<h3>Liability for water leaks</h3>

Liability for water leaks

In the event of a water leak within your property’s boundary, hundreds of cubic meters of water can quickly be lost. With a water meter, you would be liable for the cost of this wasted water, which would not be the case if you did not have one.

<h3>Surprising water bills</h3>

Surprising water bills

Without a water meter, water bills tend to be predictable and consistent. Despite annual increases in water rates, the amount you pay remains relatively stable over time. However, with a water meter, your bills will vary based on your consumption, potentially leading to unexpected costs.

<h3>It's a one way decision</h3>

It's a one way decision

The lowest bill guarantee ensures that you won’t pay more for your water in the first two years after installing a water meter. However, once this period ends, you must pay according to a measured water tariff, which could be more expensive than your previous unmetered rate.

How to get back to unmetered charges

In most parts of the UK, opting for a water meter installation includes a two-year guarantee that your bills will not increase.

Should your initial bill post-installation prove more expensive, you can typically request to revert to a rateable value or assessed water tariff. Some water companies may perform this evaluation automatically.

It is advisable to thoroughly review the terms and conditions associated with your supplier’s “lowest bill guarantee.”

⚠️ In areas experiencing significant water scarcity—such as parts of Southern Water, South East Water, Thames Water, Affinity Water, and SES Water—the lowest bill guarantee may not be applicable.

How to request a water meter

You can request a water meter from your local water company’s website.

💡Check out our who is my water supplier page if you’re unsure who this is.

Here’s the process once you’ve requested a water meter:

  • Water meter survey – An engineer from your water company will visit your property to determine the most suitable location for the water meter. This could be either inside your home or on the pavement outside.
  • Water meter installation – An engineer will fit a water meter into your home’s incoming potable water pipe. The meter will start with a zero reading and begin to record your home’s water consumption.
  • Your new water tariff – Following the installation of the water meter, your water company will switch your account to a measured water tariff. From your next bill onwards, you will be charged according to your area’s measured tariff rules.

Water meter calculator – FAQ’s

Our water experts answer those frequently asked questions regarding domestic water meters.

How much does it cost to request a water meter?

In England and Wales, requesting a water meter installation is usually free of charge.

However, this service is provided at no cost only if it is “practical and not unreasonably expensive” to install the water meter. Should these conditions not be met, your water company might switch your supply to an assessed tariff, considering the unique aspects of your home.

💡 Assessed tariffs differ among water companies. For more detailed information, we recommend consulting your local water company’s website.

Who can benefit the most from a water meter?

Owing to how water tariffs are structured, homes of high value with fewer occupants stand to gain significantly from water metering.

Under the rateble value tariff commonly applied to homes without a water meter, your bills are primarily determined by the property’s value. This means you could face high bills despite minimal water usage at your home.

How long does it take for a water meter installation?

Installing a water meter onto your water pipe is usually completed in less than an hour, during which time your water supply will be temporarily disconnected.

Regrettably, many water companies may require several weeks to schedule an engineer to conduct the survey and install the meter.

The timeframe largely depends on the available resources of your local water company.

Can my water company force me to install a water meter?

Yes, in areas facing significant water scarcity, water companies can mandate the installation of a water meter at your property.

Universal water metering reduces the risk of water shortages and is currently being used by Southern Water, South East Water, Thames Water, Affinity Water, and SES Water.

For more information, consult CCW’s statement on compulsory metering.

Is it cheaper to have a water meter?

Whether a water meter will save you money depends on several factors:

  • The actual volume of water your household consumes.
  • The rateable value of your property.
  • The specific tariff rules set by your local water company.

Our water meter calculator estimates if your particular household could benefit from reduced water bills by switching to a water meter.

How often is my water meter read?

According to Ofwat, the regulatory body for the water industry, water companies must carry out a meter reading at least once per year.

For billing periods between these readings, your water company will apply an estimated usage figure to your bills.

Increasingly, some water companies are adopting smart water meters, facilitating automatic meter readings.

How are my meter readings sent to my supplier?

There are several methods for transmitting water meter readings to your supplier:

  • Your supplier will conduct their own manual reading at least once a year.
  • You can submit a meter reading yourself and send it to your supplier via their website.
  • If you have a smart water meter, your readings will be transmitted automatically to your supplier.