How our calculator works

Customers in Britain cannot switch water or sewerage companies; they can however choose to be on a water meter. The uSwitch.com water calculator is designed to show customers if they could save money by switching to a water meter. We can also provide them with additional water saving ideas.

In order to calculate each customer’s consumption the calculator asks a series of questions about the water usage of the household. The answers to these questions are then used to calculate the water usage based on a set of consumption profiles for each detailed activity. The consumption profiles are then used to calculate costs and water savings.

In order to work out how much a customer’s bill could be if they were on a water meter the water calculator looks at the following things:

• the water supply company – this ensures the calculator selects the correct tariff information for the customer
• the sewerage company – some customers have a different sewerage company from the water supply company
• current bill size – customers enter what they currently pay each year. If the customer is unsure then this can be left blank and an industry average is used for their water and sewerage company
• standing charge – each tariff includes a standing charge for water and sewerage. This is a fixed amount that a customer must pay each year no matter how much water they use
• volumetric charge – each tariff also includes a charge for every unit (m3) of water used in the household. (This also includes a charge for sewerage)

The water calculator takes the calculated water consumption and the selected tariff structure and calculates the bill size for the customer if they were on a water meter.

If the customer will not make a saving by switching to a meter, we will show a negative value in the savings column of the results table.

The calculator also allows users to see how much water they could save by implementing a series of water saving ideas.

One example is reducing the amount of water that simply gets flushed down the toilet. By putting a water saving device like a ‘Hippo’ or ‘Save a Flush’ in the toilet cistern the amount of water that gets flushed away can be reduced. Water companies provide these devices for free to their customers. If this method of saving water is right for customers they can request a water saving device, via uSwitch, from their water company.