A family of 5 buys about 1,806 bottles a year. That is roughly $735. A home system costs most of it up front, then a little a year. So when does it win? At these assumptions, the tankless RO could pay for itself in about 2.2 years.
Every number is an assumption you can move. Bottled-water numbers come from U.S. industry data. System prices are our list prices.
Default: U.S. average, 47.7 gallons per person in 2025 (IBWA / Beverage Marketing Corporation).
Default: $3.08, the 2024 U.S. retail average (IBWA).
Only used to count bottles.
Our list price.
The HW800 filter plan price.
Our list price. Includes the tankless RO.
A rough estimate. Swap in your own.
No electricity or water-waste cost is counted for either system. Installation is not included unless it is in the price you enter.
At these assumptions, 5 people buy about 1,806 bottles a year, roughly $735 of bottled water. The tankless RO could pay for itself in year 2.2. The whole-home system could pay for itself in year 6.6.
Cumulative cost ($) since day one
Years
At these assumptions, a family could save a few thousand dollars and skip a lot of plastic.
Tankless RO: against bottled water over 10 years
Could save $4,256
$7,346 bottled vs $3,090 for the RO system with upkeep. Break-even in year 2.2.
Whole-home system: against bottled water over 10 years
Could save $1,646
$7,346 bottled vs $5,700 for the whole-home system with upkeep. Break-even in year 6.6.
Plastic bottles avoided over 10 years, if the system replaces all bottled drinking water
18,064
About 1,806 bottles a year at 16.9 oz each (0.132 gal).
1 icon = 500 bottles.
Bottled water per person. 47.7 gallons per person in 2025, from Beverage Marketing Corporation data released May 2026 for the International Bottled Water Association (IBWA), as reported by The Shelby Report (May 16, 2026) and Vending Market Watch (June 3, 2026). The 2024 figure was 47.3 gallons (Beverage Marketing Corporation, beveragemarketing.com).
Bottled price per gallon. The 2024 U.S. retail average: $49.9 billion of sales divided by 16.2 billion gallons, both from the IBWA 2024 Progress Report (Beverage Marketing Corporation, preliminary). It is an average across all bottle sizes and delivery types, not what any one household pays.
Our systems. Prices are our list prices: $1,200 for the tankless RO and $3,200 for the whole-home system, which includes the tankless RO. RO upkeep is the $189 a year HW800 filter plan. Whole-home upkeep of $250 a year is our estimate.
Method. Bottled cost in year t = people x gallons per person x price per gallon x t. A system costs its price plus its yearly upkeep x t. Break-even is the year the two lines cross: price / (bottled cost per year - upkeep per year). Savings are bottled cost minus system cost at year 10. Bottles avoided = gallons per year / 0.132 x 10. Bottled-water use is held constant, with no price changes or inflation. These are estimates at your assumptions, not a quote or a guarantee.
At these assumptions, a family of 5 that replaces all its bottled drinking water could break even on a $1,200 tankless RO in about 2.2 years and on a $3,200 whole-home system in about 6.6 years. Your numbers will differ, so use the sliders.
The U.S. average is 47.7 gallons per person in 2025, per Beverage Marketing Corporation data released for the International Bottled Water Association. For a family of 5 that is about 238 gallons a year.
It costs more up front, and this page only counts drinking water. A whole-home system also treats showers, laundry and appliances, which this comparison leaves out.
Yes. The RO uses the $189 a year HW800 filter plan price. The whole-home upkeep is an estimate. Electricity, water waste and installation are not included.