Water · Best-of

Cheapest Water Filter Per Gallon

Sticker price hides the real cost: cartridge price divided by rated gallons. A cheap pitcher with tiny cartridges can cost more per gallon than an under-sink system. We compute cost per gallon for every unit and rank by it here.

How we score: We exclude units with no public filter price, then rank by computed cost per gallon, lowest first.

1. 13.7

   SpringWell CF1 Whole House$0.000/gal

   The SpringWell CF1 Whole House is a whole house water filter. It carries no accredited NSF, WQA, or IAPMO certification - its contaminant claims are "tested to" lab results, not certifications. It is also marketed for chlorine taste and odor, chloramine, VOCs, PFAS, pesticides, herbicides, lead, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.000 per gallon.

   • Certified to reduce: nothing certified (claims are 'tested to' only)
   • Cartridge life: 1,000,000 gallons
   • Cost per gallon: $0.000
2. 23.8

   Aquasana Rhino EQ-1000 Whole House$0.001/gal

   The Aquasana Rhino EQ-1000 Whole House is a whole house water filter. It is third-party certified (NSF/WQA) to reduce chlorine taste and odor. It is also marketed for chloramine, sediment, rust, VOCs, herbicides, pesticides, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.001 per gallon.

   • Certified to reduce: chlorine taste and odor
   • Cartridge life: 1,000,000 gallons
   • Cost per gallon: $0.001
3. 35.7

   Waterdrop 10UA Under-Sink$0.005/gal

   The Waterdrop 10UA Under-Sink is a under sink water filter. It is third-party certified (IAPMO) to reduce chlorine taste and odor. It is also marketed for PFAS, PFOA, PFOS, lead, sediment, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.005 per gallon.

   • Certified to reduce: chlorine taste and odor
   • Cartridge life: 8,000 gallons
   • Cost per gallon: $0.005
4. 46.0

   Express Water RO5DX 5-Stage RO$0.021/gal

   The Express Water RO5DX 5-Stage RO is a ro water filter. It is third-party certified (NSF) to reduce total dissolved solids (TDS). It is also marketed for lead, arsenic, fluoride, chromium, mercury, uranium, radium, chlorine taste and odor, chloramine, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.021 per gallon.

   • Certified to reduce: total dissolved solids (TDS)
   • Cartridge life: 4,380 gallons
   • Cost per gallon: $0.021
5. 56.1

   iSpring RCC7 5-Stage RO$0.024/gal

   The iSpring RCC7 5-Stage RO is a ro water filter. It is third-party certified (NSF) to reduce total dissolved solids (TDS). It is also marketed for lead, fluoride, arsenic, cadmium, chromium, copper, selenium, chlorine taste and odor, PFAS, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.024 per gallon.

   • Certified to reduce: total dissolved solids (TDS)
   • Cartridge life: 547,500 gallons
   • Cost per gallon: $0.024
6. 63.2

   Big Berkey Gravity System$0.028/gal

   The Big Berkey Gravity System is a countertop water filter. It carries no accredited NSF, WQA, or IAPMO certification - its contaminant claims are "tested to" lab results, not certifications. It is also marketed for lead, PFOA, PFOS, chlorine taste and odor, fluoride, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.028 per gallon.

   • Certified to reduce: nothing certified (claims are 'tested to' only)
   • Cartridge life: 6,000 gallons
   • Cost per gallon: $0.028
7. 76.8

   Frizzlife SK99 Under-Sink Filter$0.031/gal

   The Frizzlife SK99 Under-Sink Filter is a under sink water filter. It is third-party certified (IAPMO) to reduce chlorine taste and odor, lead. It is also marketed for chloramine, mercury, cadmium, fluoride, VOCs, PFOA, PFOS, sediment, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.031 per gallon.

   • Certified to reduce: chlorine taste and odor, lead
   • Cartridge life: 1,600 gallons
   • Cost per gallon: $0.031
8. 84.3

   Home Master TMAFC-ERP Artesian RO$0.038/gal

   The Home Master TMAFC-ERP Artesian RO is a ro water filter. It carries no accredited NSF, WQA, or IAPMO certification - its contaminant claims are "tested to" lab results, not certifications. It is also marketed for chlorine taste and odor, chloramine, lead, fluoride, total dissolved solids (TDS), arsenic, pharmaceuticals, microplastics, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.038 per gallon.

   • Certified to reduce: nothing certified (claims are 'tested to' only)
   • Cartridge life: 27,375 gallons
   • Cost per gallon: $0.038
9. 97.5

   Culligan US-EZ-4 Under-Sink$0.091/gal

   The Culligan US-EZ-4 Under-Sink is a under sink water filter. It is third-party certified (IAPMO) to reduce chlorine taste and odor, chloramine, lead, mercury, cysts, VOCs, MTBE, turbidity, PFOA, PFOS. It is also marketed for pharmaceuticals, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.091 per gallon.

   • Certified to reduce: chlorine taste and odor, chloramine, lead, mercury, cysts, VOCs, MTBE, turbidity, PFOA, PFOS
   • Cartridge life: 500 gallons
   • Cost per gallon: $0.091
10. 104.9

    Waterdrop G3P800 Tankless RO$0.123/gal

    The Waterdrop G3P800 Tankless RO is a ro water filter. It is third-party certified (IAPMO) to reduce chlorine taste and odor, total dissolved solids (TDS), lead, fluoride, cadmium, chromium-6, selenium. It is also marketed for PFOA, PFOS, arsenic, nitrate, mercury, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.123 per gallon.

    • Certified to reduce: chlorine taste and odor, total dissolved solids (TDS), lead, fluoride, cadmium, chromium-6, selenium
    • Cartridge life: 2,200 gallons
    • Cost per gallon: $0.123
11. 114.0

    APEC ROES-50 Essence RO$0.145/gal

    The APEC ROES-50 Essence RO is a ro water filter. It is third-party certified (WQA) to reduce total dissolved solids (TDS). It is also marketed for chlorine taste and odor, lead, arsenic, fluoride, VOCs, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.145 per gallon.

    • Certified to reduce: total dissolved solids (TDS)
    • Cartridge life: 550 gallons
    • Cost per gallon: $0.145
12. 127.2

    Aquasana AQ-5200 Under-Sink$0.148/gal

    The Aquasana AQ-5200 Under-Sink is a under sink water filter. It is third-party certified (WQA) to reduce lead, chlorine taste and odor, chloramine, PFOA, PFOS, VOCs. Running cost works out to about $0.148 per gallon.

    • Certified to reduce: lead, chlorine taste and odor, chloramine, PFOA, PFOS, VOCs
    • Cartridge life: 500 gallons
    • Cost per gallon: $0.148
13. 137.3

    Brita Elite Pitcher (10-Cup)$0.167/gal

    The Brita Elite Pitcher (10-Cup) is a pitcher water filter. It is third-party certified (IAPMO) to reduce chlorine taste and odor, lead, mercury, cadmium, asbestos, benzene, particulates. Running cost works out to about $0.167 per gallon.

    • Certified to reduce: chlorine taste and odor, lead, mercury, cadmium, asbestos, benzene, particulates
    • Cartridge life: 120 gallons
    • Cost per gallon: $0.167
14. 144.1

    Epic Smart Shield Under-Sink$0.177/gal

    The Epic Smart Shield Under-Sink is a under sink water filter. It is third-party certified (IAPMO) to reduce chlorine taste and odor, lead, VOCs, chloramine, mercury, cysts, pharmaceuticals. It is also marketed for PFAS, PFOA, PFOS, microplastics, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.177 per gallon.

    • Certified to reduce: chlorine taste and odor, lead, VOCs, chloramine, mercury, cysts, pharmaceuticals
    • Cartridge life: 651 gallons
    • Cost per gallon: $0.177
15. 156.0

    Brita Faucet Mount (Elite)$0.180/gal

    The Brita Faucet Mount (Elite) is a faucet water filter. It is third-party certified (WQA) to reduce lead, chlorine taste and odor. It is also marketed for benzene, asbestos, microplastics, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.180 per gallon.

    • Certified to reduce: lead, chlorine taste and odor
    • Cartridge life: 100 gallons
    • Cost per gallon: $0.180
16. 161.7

    Clearly Filtered 3-Stage Under-Sink$0.198/gal

    The Clearly Filtered 3-Stage Under-Sink is a under sink water filter. It carries no accredited NSF, WQA, or IAPMO certification - its contaminant claims are "tested to" lab results, not certifications. It is also marketed for chlorine taste and odor, fluoride, lead, PFAS, PFOA, PFOS, arsenic, mercury, chromium, pesticides, pharmaceuticals, VOCs, chloramine, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.198 per gallon.

    • Certified to reduce: nothing certified (claims are 'tested to' only)
    • Cartridge life: 2,000 gallons
    • Cost per gallon: $0.198
17. 175.6

    Brita Standard Pitcher$0.200/gal

    The Brita Standard Pitcher is a pitcher water filter. It is third-party certified (WQA) to reduce chlorine taste and odor, zinc, copper, cadmium, mercury. Running cost works out to about $0.200 per gallon.

    • Certified to reduce: chlorine taste and odor, zinc, copper, cadmium, mercury
    • Cartridge life: 40 gallons
    • Cost per gallon: $0.200
18. 185.4

    PUR Plus Faucet Mount (PFM400H)$0.250/gal

    The PUR Plus Faucet Mount (PFM400H) is a faucet water filter. It is third-party certified (NSF) to reduce lead, chlorine taste and odor, mercury. It is also marketed for microplastics, benzene, asbestos, pesticides, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.250 per gallon.

    • Certified to reduce: lead, chlorine taste and odor, mercury
    • Cartridge life: 100 gallons
    • Cost per gallon: $0.250
19. 197.2

    AquaTru Classic Countertop RO$0.287/gal

    The AquaTru Classic Countertop RO is a ro water filter. It is third-party certified (IAPMO) to reduce lead, PFOA, PFOS, fluoride, arsenic, chromium-6, nitrate, chlorine taste and odor, chloramine, VOCs. It is also marketed for microplastics, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.287 per gallon.

    • Certified to reduce: lead, PFOA, PFOS, fluoride, arsenic, chromium-6, nitrate, chlorine taste and odor, chloramine, VOCs
    • Cartridge life: 600 gallons
    • Cost per gallon: $0.287
20. 202.7

    LifeStraw Home Pitcher$0.288/gal

    The LifeStraw Home Pitcher is a pitcher water filter. It carries no accredited NSF, WQA, or IAPMO certification - its contaminant claims are "tested to" lab results, not certifications. It is also marketed for lead, mercury, chromium, cadmium, copper, chlorine taste and odor, PFOA, PFOS, microplastics, bacteria, parasites, pesticides, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.288 per gallon.

    • Certified to reduce: nothing certified (claims are 'tested to' only)
    • Cartridge life: 264 gallons
    • Cost per gallon: $0.288
21. 213.2

    Epic Pure Pitcher$0.353/gal

    The Epic Pure Pitcher is a pitcher water filter. It carries no accredited NSF, WQA, or IAPMO certification - its contaminant claims are "tested to" lab results, not certifications. It is also marketed for fluoride, lead, PFOA, PFOS, chromium-6, chlorine taste and odor, benzene, microplastics, pesticides, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.353 per gallon.

    • Certified to reduce: nothing certified (claims are 'tested to' only)
    • Cartridge life: 150 gallons
    • Cost per gallon: $0.353
22. 224.9

    PUR Plus Pitcher (7-Cup)$0.374/gal

    The PUR Plus Pitcher (7-Cup) is a pitcher water filter. It is third-party certified (NSF/WQA) to reduce chlorine taste and odor, lead, mercury. It is also marketed for microplastics, copper, zinc, cadmium, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.374 per gallon.

    • Certified to reduce: chlorine taste and odor, lead, mercury
    • Cartridge life: 40 gallons
    • Cost per gallon: $0.374
23. 232.5

    Clearly Filtered Pitcher$0.495/gal

    The Clearly Filtered Pitcher is a pitcher water filter. It is third-party certified (NSF) to reduce chlorine taste and odor. It is also marketed for lead, fluoride, PFOA, PFOS, PFAS, arsenic, microplastics, chromium-6, mercury, for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $0.495 per gallon.

    • Certified to reduce: chlorine taste and odor
    • Cartridge life: 100 gallons
    • Cost per gallon: $0.495
24. 244.9

    ZeroWater 5-Stage Pitcher (7-Cup)$1.167/gal

    The ZeroWater 5-Stage Pitcher (7-Cup) is a pitcher water filter. It is third-party certified (IAPMO) to reduce chlorine taste and odor, lead, chromium-6, mercury, PFOA, PFOS. It is also marketed for total dissolved solids (TDS), for which we found no accredited third-party certification (so we award no certification credit; this is not a finding that it fails to reduce them). Running cost works out to about $1.167 per gallon.

    • Certified to reduce: chlorine taste and odor, lead, chromium-6, mercury, PFOA, PFOS
    • Cartridge life: 15 gallons
    • Cost per gallon: $1.167