How to Choose the Right Air Filter Size

Fit Is Everything

Even the best filter fails if it is the wrong size. A filter that is too small lets air bypass around it; one that is too large won't seat properly. Getting the dimensions right is the first step to clean air.

How to Measure

Filters are measured as length x width x depth.

1. Check the existing filter — the size is often printed on the cardboard frame

2. No label? Measure the filter itself, or the slot it sits in, in millimetres

3. Record all three dimensions — length, width and depth (thickness) all matter

Take a photo of the old filter and its slot too — it helps us confirm the right fit.

When There's No Standard Size

Plenty of systems — especially older or commercial ones — don't take a standard off-the-shelf size. Forcing in the nearest size leaves gaps and lets unfiltered air through.

This is where custom manufacturing solves the problem: a filter built to your exact dimensions fits snugly, eliminates bypass and performs as intended.

Not Sure? Send Us the Details

Measure up or send us a photo, and we'll identify the right filter — and make it to size if needed. Call 07 3800 3448 or request a quote.