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FilterScored

Data report · 2026

The true cost of clean air and water

We score every air purifier and water filter on the running cost manufacturers hide and the certifications they blur. This report aggregates what those numbers look like across our catalog of 25 air purifiers and 25 water filters. Every figure is computed from the same data behind the scorecards, so it updates as the catalog grows.

Air purifiers

$84
Median annual filter cost across scored air purifiers
52%
Publish an AHAM-verified CADR (the rest ask you to trust a marketing number)
9
of 25 use an ionizer or ozone-generating stage
13
overstate their room-size coverage versus their own CADR

The cheapest air purifier to run in our set is the GermGuardian AC4825E at about $24.99/year in filters. The priciest is the Molekule Air Pro at about $349.98/year - roughly 14x more, for filters alone.

Over five years, total cost of ownership ranges from about $224.94 (GermGuardian AC4825E) to about $2749.89 (Molekule Air Pro). Sticker price is a poor guide to either.

Water filters

$0.167
Median cost per gallon across scored water filters
72%
hold at least one accredited NSF/WQA/IAPMO certification
7
of 25 make contaminant claims with zero accredited certification ('tested to', not 'certified to')
11
market lead or PFAS removal they are not certified for

Cost per gallon spans a wide range: from about $0.001/gal (Aquasana Rhino EQ-1000 Whole House) to about $1.167/gal (ZeroWater 5-Stage Pitcher (7-Cup)). Pitchers with small cartridges are usually the most expensive water you can filter, despite the low sticker price.

The headline finding is the one our whole methodology is built on: a meaningful share of popular water filters make lead or PFAS claims with no accredited certification behind them. A claim is not a certification. See our guide on the difference.

Method

Figures are computed across every product on FilterScored at the time of writing. Annual filter cost is replacement-filter price times replacements per year; cost per gallon is cartridge price divided by rated gallons. Certification counts reflect only certifications verifiable on an official NSF, WQA, or IAPMO database. Products with no public replacement-filter price are excluded from cost figures and labeled on their scorecards. See the full methodology.