Pitchers are cheap to buy, need no installation and suit renters, but their cartridges filter only about 40 to 100 gallons each and refilling is slow. Under-sink filters cost more upfront and need a simple plumbing connection, but deliver filtered water on tap, last hundreds of gallons per cartridge and often cost less per gallon. Check that whichever you choose is certified for your contaminants.
Both filter drinking water at the kitchen. The difference is how much water you need, how fast, and what you will pay over a few years.
At a glance
| Pitcher or dispenser | Faucet mount | Under-sink | |
|---|---|---|---|
| Install | None | Screws onto faucet | Connects to cold line |
| Rated capacity per cartridge | About 40 to 100 gal | About 100 to 200 gal | About 500 to 1,500 gal or more |
| Flow | Gravity, slow | Faucet flow, reduced | Near faucet flow |
| Space | Fridge or counter | Faucet | Cabinet |
| Best for | Renters, small households | Renters, moderate use | Families, cooking and drinking |
Ranges reflect typical certified models; check each product’s listing.
Work out cost per gallon
Cost per gallon = cartridge price ÷ rated gallons. Then estimate use: a household drinking and cooking with 2 gallons a day uses about 730 gallons a year.
| Example | Cartridge price | Rated gallons | Cost per gallon | Yearly at 730 gal |
|---|---|---|---|---|
| Pitcher | $15 | 40 | $0.38 | About $274 |
| Under-sink | $60 | 750 | $0.08 | About $58 |
The prices are examples to show the math. Use current prices for the models you are considering.
Certification beats format
A pitcher certified to NSF/ANSI 53 for lead beats an uncertified under-sink unit. Look up the model in the certifier’s listing; our certification guide shows how.
When to step up
If your test shows dissolved contaminants such as nitrate, arsenic or high total dissolved solids, neither suits; you need reverse osmosis. Browse drinking-water filters.
Common questions
Are pitcher filters as good as under-sink filters?
Some pitchers carry strong NSF/ANSI 53 and 401 certifications. The difference is mostly capacity, convenience and cost per gallon, not quality.
How often do pitcher filters need replacing?
Often every 40 to 100 gallons, which is about one to two months for many households. Check the rated capacity.
Can renters install an under-sink filter?
Many under-sink filters connect to the cold-water line with a tee adapter and no drilling. Ask your landlord and keep the original parts.
How do I compare running costs?
Divide the cartridge price by its rated gallons to get cost per gallon, then multiply by your yearly use.