Estimate the cartridge cost of filtered water using the replacement price, rated capacity, daily consumption, and an optional allowance for flushing or wastewater. The result helps compare filters with different prices and service lives on the same basis.
Cost per Gallon Calculator
Estimate cost per gallon and monthly cost from filter price, capacity, and your daily use. Currency-agnostic: enter your local prices.
How to use the cost-per-gallon calculator
- Enter the current price of one replacement cartridge in your preferred currency.
- Use the manufacturer’s rated capacity in gallons, then add your estimated daily filtered-water use.
- Select a waste factor only when the system uses extra water for flushing or produces reject water.
What the estimate includes
The calculation covers replacement-cartridge cost. It does not include the initial housing, faucet, storage tank, installation, electricity, testing, or maintenance parts. Actual capacity can also be lower when sediment, contaminant levels, pressure, or water chemistry differ from the manufacturer’s test conditions.
Use the result as a planning comparison rather than a guaranteed operating cost. For additional tools, visit the complete calculator hub or review our maintenance and replacement guidance.