At the current one-time price of about $45 per cartridge and a 60–90 day interval, annual replacement spend is roughly $180 to $270 before discounts. Subscription pricing can reduce that materially.
One-time cartridge pricing
Filterbaby currently lists the Pro replacement cartridge around $45 one-time. The company recommends replacement every 60–90 days depending on water quality and usage.
That produces a simple annual range of four to six cartridges.
Annualized cost
Four cartridges at $45 equals about $180 per year. Six cartridges equals about $270 per year.
A household with cleaner water and moderate use may land closer to the lower end, while heavy use or faster fouling can push replacement frequency upward.
Subscription economics
Filterbaby offers lower subscription pricing and multi-pack discounts. The value depends on whether the user actually needs the advertised replacement cadence and is comfortable with recurring deliveries.
Compare the system, not just the hardware price
A $100–$140 faucet device can look inexpensive next to under-sink filtration, but three years of cartridges can cost several times the initial hardware price.
That does not make the system poor value; it simply means recurring cost belongs in the purchase decision.
Match the treatment scope to the source for Filterbaby Replacement Filter Cost: 1-Year and 3-Year Ownership
Portable, faucet and shower filters solve very different problems depending on the incoming water. A product intended for treated municipal water should not be assumed to make microbiologically unsafe surface water drinkable. Likewise, a shower filter that improves chlorine exposure is not a substitute for a drinking-water system certified for lead, PFAS or other ingestion concerns.
Check the exact contaminant claims, rated flow and cartridge life. For portable purifier claims, independently documented pathogen performance matters. For faucet or shower products, pressure drop and replacement frequency matter because a cartridge that is unpleasant to use will often be bypassed or kept in service too long.
Replacement cost and practical usability
Calculate cost per month or per gallon using a realistic replacement interval rather than the maximum advertised capacity alone. Source-water quality and daily volume can shorten life, while calendar replacement limits may matter even when the theoretical gallon rating has not been reached.
Also consider proprietary cartridges, housing availability and whether replacement filters can be purchased reliably in your region. Convenience is part of performance: weight, flow resistance, shower pressure or faucet clearance can determine whether the product remains in regular use.