How Often to Replace Every Filter in Your Home (The One-Table Answer)
Every filter in a typical American home runs on a different clock — the fridge cartridge every 6 months, the 1-inch HVAC filter every 60–90 days, the 4-inch media filter every 6–12 months, RO stages on a 12-month rotation, and the rest scattered between 1 month and a year. No single “filter schedule” exists in nature, which is exactly why households default to replacing whatever they happen to remember. This page puts every clock in one table, then shows the tool that remembers them for you.
Top Picks at a Glance (2026)
Every filter in the house ages on its own clock; these three picks cover the three shortest clocks — fridge water, fridge air, and the HVAC slot:
| Pick | Product | Why it wins |
|---|---|---|
| Fridge water — 6 months | EDR1RXD1-compatible cartridge (1-pack) | 200-gallon / 6-month rated life, coconut-shell carbon tested to NSF/ANSI 42 protocols; the calendar’s anchor date. |
| Fridge air — same 6 months | FreshFlow AIR1-compatible air filter (2-pack) | Carbon odor media rated 15x baking soda with a month 1-6 indicator strip; two cartridges cover a full year in sync with the water filter. |
| HVAC slot — 90 days | 20x20x1 MERV 8 pleated (1-pack) | 90-day rated cadence at the baseline tier; four a year is the cheapest calendar in the house to keep. |
The Whole-House Replacement Table
| Filter | Standard interval | What shortens it | Deep dive |
|---|---|---|---|
| Refrigerator water cartridge | 6 months / rated gallons | Heavy use, poor source water | Guide |
| HVAC/furnace 1-inch | 60–90 days | Pets, construction dust, MERV 13 | Guide |
| HVAC 4–5″ media | 6–12 months | Same as above, buffer included | Guide |
| RO system (3-stage) | Sediment 12 mo / carbon 6–12 mo / membrane 24 mo | Hard water, chloramine | Guide |
| Whole-house POE | Media-dependent, 3–10 yrs by stage | Iron, sediment load | Guide |
| Water filter pitcher | 40–120 gal (1–2 months typical) | Capacity, not calendar | — |
| Pool filter cartridge | 1–2 seasons; clean at +8–10 psi | Bathing load, debris | — |
| Humidifier wick/pad | 1–3 months (seasonal) | Hard water scale kills wicks | — |
| Range hood grease filter | 2–3 months (washable monthly) | Cooking frequency | — |
| Vacuum HEPA/exhaust | 6–12 months | Pet households | — |
| Coffee maker (carbon) | ~2 months | Daily brewing | — |
| CPAP machine filter | Monthly (fine white pad) | Dusty bedroom | — |
| Under-sink drinking water | 6–12 months by stage | Same as RO | Guide |
| Air purifier HEPA | 12 months; carbon pre-filter 3 mo | Wildfire season, pets | — |
| Fridge air filter | 6 months (with the water cartridge) | Odorous foods | — |
| Ice maker filter (standalone) | 6–12 months | Same as fridge cartridge | — |
| Shower filter (KDF/carbon) | 4–6 months | Hard water | — |
| Bathroom/vent fan grill | Wash 6 months (not a cartridge, but same forgetting) | — | — |
The pattern hiding in the table: almost everything clusters on either a ~90-day rhythm or a ~6-month rhythm. That accident of engineering is what makes a consolidated calendar workable at all — you are not juggling sixteen schedules, you are running two.
For the refrigerator row, the EDR1RXD1 3-pack covers a year and a half of the six-month cadence at a lower per-filter cost.
What the Table Cannot Do
Intervals shift with the household. Two shedding dogs take a 90-day HVAC filter to 45 days. A family of six on a fridge dispenser hits the cartridge’s gallon rating before its six months. A wildfire month can load an air purifier’s carbon in weeks. The table is the median; your house is a specific point. The brand-level deep-dive guides linked in each row cover the adjustment factors in detail.
The other thing the table cannot do is fire a reminder. Paper tables get taped inside a cabinet door and forgotten by the second cycle — this is not a discipline failure, it is the absence of a system. Which is the segue, and the reason this page exists.
How to Tell a Filter Is Done Before the Calendar Says So
Intervals are the schedule; the filter itself is the evidence. The two agree most of the time, and when they disagree, the evidence wins. Four signals cover most of the table:
- HVAC (1-inch and media): pull the filter and hold it up to a light. A gray, opaque mat with visible loading near the frame means replace — regardless of days remaining. A 1-inch filter bowing under airflow is the same verdict in three dimensions.
- Refrigerator cartridge: dispenser flow is the tell. When filling a glass takes noticeably longer than it did at installation, the cartridge is loading up; chlorine taste returning is the late-stage confirmation.
- RO membrane: the one stage with a number. A climbing TDS meter reading is the standard trigger to replace the membrane — not the calendar (the RO schedule keeps the two straight).
- Pool cartridge: the pressure gauge, not the seasons. +8–10 psi over the clean-filter baseline means clean or replace — the table’s “1–2 seasons” shorthand, made numeric.
The operating rule that falls out: the calendar decides when to look, the evidence decides whether to change. A filter replaced on evidence a month early is money spent well; a filter trusted for three more weeks because the calendar says so, against visible load, is the exact failure this table exists to prevent. For the signals specific to one appliance, use the deep-dive guide in that filter’s row.
The Home Filter Calendar
The Home Filter Calendar does the two things a taped table cannot:
- One inventory, one dashboard. Register each appliance once (fridge, furnace, RO, humidifier, the works). Every interval from the table above is preloaded by device type — you confirm or adjust, you do not research.
- Reminders on your schedule. Email or push, at the interval you set, per filter. The 90-day cluster arrives together; the 6-month cluster arrives together. Buying becomes a list, not a scavenger hunt.
Setup takes about five minutes for a typical home — faster than reading this table a second time. Start with the fridge and the HVAC filter (the two with real consequences for missing), add the rest whenever you touch them next: set up your filter calendar →
Prefer paper first? The printable version of exactly this table — with checkboxes — is the Home Filter Maintenance Checklist. Most households start there and graduate to reminders by the second missed cycle. Both exist because the enemy is the same: sixteen silent clocks, none of which ring.
Related: How Often to Change a Refrigerator Water Filter · How Often to Change Your HVAC Filter · RO Replacement Schedule
Find your filter: Shop all filters