A pitcher costs almost nothing to buy and a surprising amount to run; a gravity or under-sink filter is the other way round. So the honest number is not the sticker price, it is what each gallon costs once you keep buying replacement filters. Tell it how much water you use and it ranks every filter by real cost per gallon.
Prices reviewed 31 July 2026 . Unit prices and typical replacement-filter costs in USD; your water hardness changes how long a filter lasts. Not a substitute for a lab water test.
We costed 17 home water filters by their real running cost: the replacement filter price divided by its manufacturer-rated life in gallons. The cheapest is the gravity-fed Big Berkey at $0.03 a gallon; the most expensive pitcher Clearly Filtered at $0.60. Single-use bottled water runs over $1.20 a gallon.
Method: replacement filter price ÷ manufacturer-rated filter life in gallons. Rated life assumes average tap water; hard or high-TDS water shortens it (notably ZeroWater). Unit price is listed separately and, in the tool, spread across the gallons you use. Prices are indicative USD. Cite this: "usefulHQ Water Filter Cost Study 2026", usefulhq.com/water-filter-cost/. Figures update as prices are reviewed.
The per-gallon filter cost is what compounds. A bigger household drinks more, so the cheap-to-run systems pull ahead fast.
| Filter | Type | Unit price | Per gallon | Total over term | All-in per gallon | Best for | |
|---|---|---|---|---|---|---|---|
| Big Berkey (2 Black elements)Best value Two Black Berkey elements last about 6,000 gallons combined, so the running cost is tiny; high upfront and needs counter space. | Gravity | $385 | $0.03 | $451 | $0.21 | Cheapest per gallon | Check price |
| Refrigerator filter (aftermarket) Third-party fridge filters cost a fraction of the branded ones for the same ~300-gallon life, if your fridge dispenses water. | Fridge | $15 | $0.05 | $125 | $0.06 | Cheap fridge water | Check price |
| Waterdrop Lucid pitcher A 200-gallon filter roughly triples Brita Standard's life, so it is the cheapest pitcher to run. | Pitcher | $30 | $0.06 | $161 | $0.07 | Cheapest pitcher to run | Check price |
| Culligan FM-25 faucet mount A 200-gallon filter is double most rivals; screws straight onto the tap. | Faucet | $20 | $0.07 | $173 | $0.08 | Cheapest faucet mount | Check price |
| Waterdrop RO (tankless) Tankless reverse osmosis; very cheap per gallon once plumbed in, though RO sends some water to drain. | Under-sink | $320 | $0.09 | $517 | $0.24 | Lowest-cost under-sink | Check price |
| Brita Elite pitcher The 120-gallon Elite filter lasts three times the Standard, making it cheaper per gallon despite costing more up front. | Pitcher | $36 | $0.11 | $277 | $0.13 | Best mainstream pitcher | Check price |
| APEC ROES-50 (RO) Classic 5-stage reverse osmosis; low running cost, some water waste, needs under-sink plumbing. | Under-sink | $210 | $0.11 | $451 | $0.21 | Proven RO system | Check price |
| Brita Standard pitcher Thirty dollars to buy, but the 40-gallon filter needs replacing every couple of months, and it adds up. | Pitcher | $30 | $0.13 | $315 | $0.14 | Cheapest to start | Check price |
| Aquasana Claryum under-sink Keeps healthy minerals and wastes no water; a 500-gallon filter set keeps the cost down. | Under-sink | $150 | $0.14 | $457 | $0.21 | No-waste under-sink | Check price |
| PUR Plus faucet mount A 100-gallon filter certified to reduce lead; quick to fit on most taps. | Faucet | $25 | $0.15 | $354 | $0.16 | Faucet, lead certified | Check price |
| Refrigerator filter (OEM) Branded fridge filters are among the priciest ways to filter, near pitcher rates for ~300 gallons. | Fridge | $45 | $0.15 | $374 | $0.17 | Convenient but dear | Check price |
| Brita faucet mount 100-gallon life; easy to install, middling running cost. | Faucet | $22 | $0.18 | $416 | $0.19 | Brita on the tap | Check price |
| PUR Plus pitcher Solid filtration and a lead claim, but the 40-gallon filter means frequent changes. | Pitcher | $30 | $0.20 | $468 | $0.21 | Popular pitcher | Check price |
| Epic Pure pitcher A 150-gallon filter and strong PFAS and lead removal, at a premium price per gallon. | Pitcher | $70 | $0.33 | $793 | $0.36 | Long-life pitcher | Check price |
| ZeroWater pitcher Five-stage filter takes water to zero TDS, but in hard water the filter dies fast, pushing cost per gallon up. | Pitcher | $35 | $0.35 | $802 | $0.37 | Best for high TDS | Check price |
| Aquagear pitcher 120-gallon filter with wide contaminant removal, but dear per gallon at list price. | Pitcher | $70 | $0.42 | $990 | $0.45 | Thorough pitcher | Check price |
| Clearly Filtered pitcher Beats most rivals in lab contaminant tests, but the priciest water on this list. | Pitcher | $90 | $0.60 | $1,404 | $0.64 | Most thorough pitcher | Check price |
By cost per gallon, a gravity system like the Big Berkey, at about 3 cents a gallon, because its elements last around 6,000 gallons. Faucet and under-sink filters follow. Pitchers cost the most per gallon, 11 to 60 cents, because their small filters run out every 40 to 150 gallons.
Yes. Rated near 40 gallons, but in hard or high-TDS water a ZeroWater filter can drop to 20 gallons or less, so cost per gallon climbs to 35 to 70 cents, among the highest of any pitcher. It removes more than a standard carbon filter, but you pay for it each swap.
Over time, often yes. It costs several hundred dollars up front, but two Black elements last about 6,000 gallons combined, roughly 3 cents a gallon. Drink a lot of filtered water for years and the low running cost repays the purchase price. Light users or renters short on space are fine with a pitcher.
For a two-person home using about 2 gallons a day, a Brita Standard pitcher runs roughly $285 in filters over three years; a Brita Elite is cheaper because its filter lasts three times as long. A gravity or under-sink system costs far less per gallon once installed. Use the tool above to spread both the unit and the filters over your own usage.