Size Guide

How to find your filter size:

1. Remove your current filter
2. Look at the cardboard frame — the size is usually printed directly on it (e.g., "20x25x1")
3. If it's not visible, measure length x width x depth (round up to the nearest whole inch)
4. Still unsure? Email us a photo at hello@filtrousa.com and we'll help you identify it

Most common sizes: 20x25x1, 20x20x1, 16x25x1, 16x20x1, 14x25x1, 14x20x1, 12x12x1, 16x24x1

Don't see your size? We offer custom sizing in 1/8" increments — contact us.

Have more questions? Visit our FAQ for answers on fit, warranty, returns, and more.