Tap Water vs Bottled Water Drain
Tap Water vs Bottled Water Cost Calculator
What this calculator does
Bottled water is convenient but expensive. This calculator compares the yearly cost of cases to a filter and refill cartridges.
The math, with a worked example
Bottled annual = cases per month × cost per case × 12. Filter annual = filter cost + refills × refill cost × 12. Four $4 cases per month costs $192 per year. A $15 filter plus two $0.50 refills per month costs $27 per year.
Why this matters
Bottled water is a subscription nobody calls a subscription: 4 cases a month is $192 a year for water, versus $27 for a filter and refills. Same water, $165 gap, decided once.
Methodology and transparency
Bottled = cases per month × price per case × 12; filter = pitcher price + refills per month × refill price × 12. The refill cadence is the assumption to check: real cartridge life depends on local water and usage, and heavy use can double the refills — which still leaves a wide gap in the worked example. Everything runs in your browser; no data is sent or stored.
Last reviewed: 2026-08-08
Common questions
Is tap water safe?
It depends on your location. A filter can address taste and many contaminants.
What about environmental cost?
This calculator only covers money. Bottled water has a much higher environmental cost.