How UK water and sewerage bills are structured
Under Ofwat regulation, metered customers pay for the volume of freshwater supplied (£/m3) and wastewater returned to the sewer (£/m3).
Water companies apply a standard 95% sewerage return assumption (assuming 5% is used for gardening or drinking) plus fixed annual standing charges.
Worked example
For a quarterly bill with 25 m3 of water consumption, clean water rate of £1.85/m3, sewerage rate of £1.65/m3, and £55 annual standing charge:
Water supply costs £46.25, sewerage costs £39.19 (at 95% return), and quarterly standing charges are £13.75, totaling £99.19 for the quarter (£1.09 per day).
Inputs for the water meter calculator
Water consumed (metered)
Volume of water consumed in cubic metres (1 m3 = 1,000 litres).
Billing cycle
Select whether your water statement is issued monthly, quarterly or annually.
Clean water supply rate
Volumetric rate per cubic metre charged by your water supplier for fresh water delivery.
Used water / sewerage rate
Volumetric charge per cubic metre for wastewater collection and treatment.
Annual standing charge (water + sewer)
Combined annual fixed charges for pipe infrastructure and meter maintenance.
CALCULATOR QUESTIONS
Water meter calculator questions
How many litres are in 1 cubic metre (1 m3) on a UK water meter?
One cubic metre is equal to exactly 1,000 litres of water (or approximately 220 imperial gallons).
Why is sewerage charged at 95% of water consumed?
Water companies recognise that a small portion of clean water is drunk, evaporated or absorbed into the garden rather than entering the wastewater drainage system.