HVAC & Furnace Air Filters · 49 sizes

The right filter, the right size, on your schedule.

Find your exact filter size in seconds, pick your MERV level, and set it to auto-deliver at 15% off. Pleated, high-quality filters — for homes, rentals, and whole properties.

Find your size Managing many units? Free audit

Popular sizes

The most-ordered residential sizes. Don’t see yours? Use the finder — we carry 49 sizes.

16 × 25 × 1Most common 20 × 25 × 1Very common 16 × 20 × 1Common 14 × 25 × 1Common 20 × 20 × 1Common 16 × 25 × 4Deep / long-life 20 × 25 × 4Deep / long-life 20 × 25 × 2Mid-depth
See all 49 sizes in the finder

How air filter sizing works

Filter sizes are written as Length × Width × Depth in inches — for example, 20x25x1. The number printed on your filter’s frame is the one you order by.

Nominal sizeThe rounded number printed on the frame. This is what you order by — e.g. 20x25x1.
Actual sizeSlightly smaller than nominal so the filter seats and seals — about ½" less per side, and 1" filters are ~¼" less deep.
Length & width are interchangeableA 16×25 and a 25×16 are the same filter. Only the depth has to match exactly.
Not sure of your size?Pull your current filter and read the frame, or measure and round up. Then find it here.
⚠ Order by the printed (nominal) size. If you measure a filter with a tape it reads slightly smaller than the number on the frame — that gap is intentional and lets it seal. Always order the nominal size, like 20x25x1.

Which MERV rating should you choose?

MERV (Minimum Efficiency Reporting Value) measures how much a filter captures. Match it to your needs and your system’s airflow — higher isn’t automatically better.

MERV 8
Everyday

Dust, lint, pollen, mold spores. The right pick for most homes and rentals.

MERV 10
A step up

Adds finer dust, pet dander, and smog particles. Good for allergy-aware homes.

MERV 13
Best air quality

Captures very fine particles — smoke, bacteria, virus carriers. Best where air quality matters most.

How often should you change your filter?

A clogged filter makes your system work harder, raises energy bills, and lets dust through. A realistic schedule for a 1" filter — deeper filters last longer.

Every 1–2 monthsHomes with pets, smokers, or allergies
Every 2–3 monthsTypical household — the sweet spot
Every 3 months maxVacant or low-use spaces

Hard to keep track? Auto-delivery ships the right filter on your schedule at 15% off — so a missed change never becomes a frozen coil or a tenant complaint. Read the full change-frequency guide →

Managing filters across multiple units?

We map every size across your property, auto-ship before you run out, and document every change for compliance. One vendor, zero reorder headaches.

Get a free site audit →

Common questions

How do I find my filter size?

Pull your current filter and read the size printed on the cardboard frame, written as length × width × depth (e.g. 20x25x1). If it’s worn off, measure all three sides and round up to the nearest inch. Then enter it in our size finder.

Does the order of the numbers matter?

Length and width are interchangeable — a 16×25 and a 25×16 are the same filter. Only the depth (the third number) has to match your system exactly.

What MERV rating do I need?

MERV 8 handles everyday dust and pollen and suits most homes. MERV 10 adds finer particles. MERV 13 captures the smallest particles and is best where indoor air quality matters most. Choose based on your needs and your system’s airflow.

How does Subscribe & Save work?

Pick your size and MERV, choose how often you want deliveries, and the right filter ships automatically at 15% below the one-time price. Skip, reschedule, or cancel anytime — no contracts.

Do you deliver to property managers and hotels?

Yes. Our managed program maps every filter size across your portfolio, auto-replenishes before you run out, and documents every change for compliance. Request a free site audit to get started.