Using your water bill to estimate total hot water usage

If your water bill is reported in Cubic Feet: Since there are 28.3 liters per cubic foot, and about the same number of days per month, you can assume the number of cubic feet used per month is about equal to the number of liters used per day.  You can multiply this number by 30% to get a very rough estimate your daily hot water usage in liters.  Using a winter water bill for this estimate is best, as it will not include water used for your lawn or garden.

Example, a household consuming 1200 cubic feet of water per month would estimate 1200 x 30% = 360 liters per day of hot water consumption.

If your water bill is reported in cubic meters: Estimate daily hot water liters by multiplying your cubic meters by 10  (1000 liters per cubic meter per month / 30 days per month multiplied by 30% to estimate hot water usage in liters).

Example, a household consuming 23 cubic meters of water per month would estimate 23 x 10 = 230 liters per day of hot water consumption.