Water bill calculator
Water tariffs differ by city, so enter the numbers from your own bill. Use the same unit for usage and prices, for example cubic metres or 1,000 gallons. Add a tier limit if the price rises above a certain amount.
Runs in your browser: nothing you enter is sent anywhere.
How to use it
- Enter the usage for the period, in the unit your bill uses.
- Enter the price per unit. If your tariff has a higher price above some amount, enter that amount as the tier limit and the higher price below it.
- Add the sewer charge per unit and any fixed charge.
- Read the total, the parts and the average cost per unit.
How it is calculated
- Without tiers: water charge = usage × price.
- With tiers: water charge = the first part (up to the limit) × price + the rest × the higher price.
- Sewer charge = usage × sewer price per unit.
- Total = water charge + sewer charge + fixed charge. Average = total ÷ usage.
Worked example
Usage 20, tier limit 10, price 2 up to the limit and 3 above it, sewer charge 1 per unit, fixed charge 8: water = 10 × 2 + 10 × 3 = 50, sewer = 20, fixed = 8, so the total is 78 and the average is 3.90 per unit.
Tips
The fixed charge makes the average cost per unit fall as usage rises, so compare the average, not only the unit price. Taxes or fees that are a percentage of the bill are not included.
Frequently asked questions
Which unit should I use?
Whatever your bill uses, as long as usage, the limit and every price use it: cubic metres, 100 cubic feet, 1,000 gallons and so on. The calculator does not convert units or currency.
How do tiers work here?
Set a tier limit above zero. Usage up to the limit is charged at the first price and only the part above it at the second price. With a limit of 0 every unit costs the first price. Some tariffs have more than two tiers; this calculator covers one step.
What is the sewer charge per unit?
Many bills add a wastewater charge based on the water you use. Enter that price per unit; it applies to all usage. Leave it at 0 if your bill has no such line or if it is already in the water price.
Where do I find my tariff?
On your bill or on your water utility's website. Prices here are only what you type in, so the result matches your bill only if you copy its prices, limits and fixed charges.