Household Bills & Lifestyle2 min check

Water Bill Calculator

Estimate your metered water and sewerage charges. Ofwat sets indicative rates per cubic metre (m³) — actual rates vary by water company.

Short answer

Metered cost per year = (water m³ × water rate) + (water m³ × sewerage rate) + standing charges. Average UK household uses ~140 litres/person/day, so 2 people use ~100 m³/year and 4 people ~200 m³/year.

Step 1 of 10%

Calculation method, coverage and version

Inputs used: People in the household, Litres per person per day, Water company / region, Are you on a water meter?.
Calculation approach: The calculator applies the rules and assumptions described in “How it works” to the values you enter. Rounding can cause small differences from an official or provider calculation.
Coverage: Household Bills & Lifestyle. UK nations, tax treatment, local rules and provider criteria can differ; check the official sources shown below before acting.
Content version: No page-specific review date is currently published. Treat the result as indicative and verify current rules independently.

Not included unless explicitly requested: personal circumstances not entered, provider discretion, future rule changes, professional fees and case-specific exceptions. Read the full calculator methodology.

How it works

We multiply household size by daily usage to get cubic metres per year, then apply your provider's water and sewerage unit rates plus standing charges.

Worked example

4 people × 140 L/day × 365 = 204 m³/year. Severn Trent: (204 × £1.85) + (204 × £2.55) + (£0.65 × 365) ≈ £898/year + £237 = ~£1,135.

Who should use this

•Households deciding whether to switch to a meter
•Tenants estimating bills before moving in
•Anyone tracking water use

Common mistakes

×Forgetting sewerage is a separate charge (often more than water)
×Using litres in the m³ formula
×Ignoring social tariffs and WaterSure if eligible

Frequently asked questions

Should I switch to a water meter?▾

Generally worth it if there are fewer occupants than bedrooms (e.g. 2 people in a 3-bed). You can switch back within 24 months if it's more expensive.

Is sewerage included?▾

Yes — most bills combine water in + waste water out. Some properties on septic tanks pay water only.

How much water does an average UK person use?▾

Around 140 litres per day per person, including showers, toilet, dishwasher, washing machine and cooking.

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