Household water use
Toilet water use calculator
Estimate annual water use and cost from toilet flushing, and what a modern cistern would save.
Result
Current annual use
49.3m³/year
With the alternative cistern
24.6m³/year
Water saved
24.6m³/year
Cost saved
49.28£/year
Note
A leaking flapper valve can waste 200–400 litres a day
Far more than flush volume. Check by adding food colouring to the cistern and seeing if it reaches the bowl unflushed.
Method
Flushes per person per day × household size × flush volume × 365, with a comparison against a stated alternative flush volume.