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27 filters ranked · prices checked Oct 17, 2026, 6:34 AM ET
The Water Index
Filters and purifiers ranked by today's price divided by the gallons the brand says the filter is rated for. When a system has parts with different ratings, we use the shortest-lived part and say so.
Store water first
Ready.gov says: Store at least one gallon of water per person per day for several days, for drinking and sanitation.
(ready.gov/water). A filter is a backup for when stored water runs out. Ratings are the manufacturer's claims. What a filter removes (bacteria, viruses, chemicals) differs a lot between models, so read the brand page before you rely on one.
Links go straight to the brand's own product page. No affiliate tags yet. If we add them, this line will say "Paid link". Rankings are pure math either way.
| Rank | Filter | $ / gallon | Price | Rated | Brand's wording |
|---|---|---|---|---|---|
| #1 | Survivor Filter Straw Ultra Filter Replacement Survivor Filter In stock | $0.0006 | $16.95 | 26,417 gal | "can be re used up to 100,000 liters (26,417 gallons)" Note: Replacement Ultra Filter element only |
| #2 | SURVIVOR FILTER™ Pure 10K - Replacement Chlorine Filter Survivor Filter In stock | $0.0080 | $80.00 | 10,000 gal | "Capacity: 10,000 gallons (37, 854 liters)" Note: Replacement chlorine filter for treated tap water |
| #3 | Puribag Micro - Mini membrane water filter Uncharted Supply Co In stock | $0.0174 | $22.99 | 1,321 gal | "Filters up to 5,000 litres of water" Note: 5,000 L converted at 3.785 L per gallon |
| #4 | Puribag Pro - Membrane Filter Kit Uncharted Supply Co In stock | $0.0227 | $29.99 | 1,321 gal | "providing up to 5,000 liters of treated water, depending on water turbidity" Note: 5,000 L converted at 3.785 L per gallon |
| #5 | LifeStraw Peak Series Straw Echo-Sigma In stock | $0.0260 | $25.99 | 1,000 gal | "Long-lasting membrane microfilter will last up to 4,000 L (1,000 gallons) of water" |
| #6 | SURVIVOR FILTER™ Max, 2-Stage Fluoride and Chlorine In-Line Home Filter Survivor Filter In stock | $0.0400 | $200.00 | 5,000 gal | "the Fluoride Filter that removes fluoride by 95% and has a 5,000 gallon (18, 927 liters) capacity" Note: Shortest-lived stage. The brand rates the All Tap stage to 8,000 gallons. For treated tap water |
| #7 | Puribag Pro Portable Water Purification System Uncharted Supply Co In stock | $0.0492 | $64.99 | 1,321 gal | "The PRO SYSTEM amplifies the Puribag's capacity from up to 120 liters to an impressive 5,000 liters" Note: 5,000 L converted at 3.785 L per gallon |
| #8 | Survivor Filter Straw Carbon Filter Replacement Survivor Filter In stock | $0.0566 | $14.95 | 264 gal | "Can be re used up to 1,000 liters (264 gallons)" Note: Replacement carbon element only |
| #9 | SURVIVOR FILTER™ Max - Replacement Stage 1 Fluoride Filter Survivor Filter In stock | $0.0588 | $100.00 | 1,700 gal | "Capacity: up to 1,700 gallons" Note: Replacement stage 1 fluoride filter for treated tap water |
| #10 | Big Berkey Stainless Steel Drip Filter System - 2 Black Berkey Filters (approx. 6000 gal.) Legacy Food Storage In stock | $0.0645 | $387.00 | 6,000 gal | "These high capacity filters provide up to 3000 gallons per filter, and 2 are included" Note: Two filters at up to 3,000 gallons each |
| #11 | Royal Berkey Stainless Steel Drip Filter System - Includes 2 Black Berkey® Filters (approx. 6000 gal.) Legacy Food Storage In stock | $0.0717 | $430.00 | 6,000 gal | "Black Berkey® high capacity filters with an approximately 3000-gallon capacity each (approx. 6000 gallons total)" Note: Two filters at about 3,000 gallons each, per the listing |
| #12 | Puribag Pro Kit - Portable 4-in-1 Water Filtration System Uncharted Supply Co In stock | $0.0757 | $99.99 | 1,321 gal | "The PRO KIT amplifies the Puribag's capacity from up to 120 liters to an impressive 5,000 liters" Note: 5,000 L converted at 3.785 L per gallon |
| #13 | LifeStraw SIP Echo-Sigma In stock | $0.13 | $34.95 | 264 gal | "the filter lasts up to 1,000 liters – over a year of daily use" Note: 1,000 L converted at 3.785 L per gallon |
| #14 | SURVIVOR FILTER PRO™ Portable Water Filter Pump Survivor Filter In stock | $0.15 | $77.95 | 528 gal | "The Carbon Filter can be reused up to 2,000 liters" Note: Shortest-lived part (2,000 L, about 528 gal). Pre-filter and Ultra Filter are rated to 100,000 liters |
| #15 | Replacement Filter for Active All Terrain and Americana Ultra Light Water Bottle, 2-Pack Survivor Filter In stock | $0.35 | $35.00 | 100 gal | "Long lasting Filter: 426 refills, 100 gallons or 3 months of daily use" Note: Replacement filter |
| #16 | Frontier Max Filter System Virus - Red line (RED-IV-120) Legacy Food Storage In stock | $0.42 | $49.99 | 120 gal | "provides up to 120 gallons of virus, bacteria, and cyst removal" |
| #17 | SURVIVOR FILTER™ Active All Terrain Filtration Bottle & Carrier System Survivor Filter In stock | $0.50 | $49.95 | 100 gal | "1x Active All Terrain Filter, 100-Gallon Capacity" |
| #18 | Frontier Pro Ultralight Water Filter - Green Line (GRN-III-50-T) Legacy Food Storage In stock | $0.60 | $29.99 | 50 gal | "Certified filtration for 50 gallons (over 180 L)" |
| #19 | Puribag Monster Bug Out 4-Pack Water Purification System Uncharted Supply Co In stock | $1.26 | $159.99 | 127 gal | "Enough capacity to treat up to 480 liters of safe, drinkable water" Note: 480 L converted at 3.785 L per gallon |
| #20 | Puribag 120L System Uncharted Supply Co In stock | $1.42 | $44.99 | 32 gal | "Enough capacity to treat up to 120 liters of safe, drinkable water" Note: 120 L converted at 3.785 L per gallon |
| – | SURVIVOR FILTER™ Pure 10K, Chlorine In-Line Home Filter Survivor Filter Sold out | $0.0100 | $100.00 | 10,000 gal | "The Filter has a 10,000 gallon (37, 854 liters) capacity" Note: In-line chlorine filter for treated tap water, not a backcountry purifier |
| – | Survivor Filter Straw Cotton Filter Pads Replacement (20 Pack) Survivor Filter Sold out | $0.0377 | $9.95 | 264 gal | "Can be re used up to 1,000 liters (264 gallons)" Note: Replacement cotton pads |
| – | SURVIVOR FILTER™ Max - Replacement Stage 2 All Tap Filter Survivor Filter Sold out | $0.0471 | $80.00 | 1,700 gal | "Capacity: up to 1,700 gallons" Note: Replacement stage 2 filter for treated tap water |
| – | SURVIVOR FILTER™ Cleanable Water Filter Straw (Model: L600 UPC Code: 628250537437) Survivor Filter Sold out | $0.14 | $36.99 | 264 gal | "Cotton Filter Pad: up to 1,000 liters (264 gallons)" Note: Shortest-lived part. The brand rates the Ultra Filter to 100,000 liters and the carbon mouthpiece and cotton pad to 1,000 liters |
| – | SURVIVOR FILTER SQUEEZE™ Water Filter + 2 Canteens Survivor Filter Sold out | $0.16 | $41.99 | 264 gal | "Cotton Filter Pad: up to 1,000 liters (264 gallons)" Note: Shortest-lived part. The Ultra Filter is rated to 100,000 liters |
| – | SURVIVOR FILTER™ PRO X Electric Survival Filter Survivor Filter Sold out | $0.19 | $99.95 | 528 gal | "The Carbon Filter can be cleaned and reused up to 2,000 liters" Note: Shortest-lived part (2,000 L, about 528 gal). Pre-filter and Ultra Filter are rated to 100,000 liters |
| – | SURVIVOR FILTER SQUEEZE™ Bundle Kit Survivor Filter Sold out | $0.34 | $88.95 | 264 gal | "Cotton Filter Pad: up to 1,000 liters (264 gallons)" Note: Shortest-lived part. The Ultra Filter is rated to 100,000 liters |
Liters are converted at 3.785 liters per gallon. Filters for treated city tap water (chlorine/fluoride) are labeled; they are not backcountry purifiers. Want storage instead? Browse all 91 water storage and filter products.