How to Measure Your Air Filter Size the Right Way!
Ever bought an air filter only to realize it doesn't fit? You're not alone! Many people assume the size written on their old filter is the exact measurement they need—but that’s not always the case. A properly sized air filter is **crucial for your HVAC system’s performance, air quality, and efficiency**. In this guide, we’ll walk you through the right way to measure your filter so you get a **perfect fit every time**!
Why Proper Filter Sizing Matters
Using the wrong size air filter can cause all sorts of issues, from **higher energy bills** to **poor indoor air quality**. Here’s why getting the correct measurement is so important:
- Prevents **air leaks**, ensuring all air is properly filtered.
- Protects your **HVAC system from dust and debris buildup**.
- Maintains **optimal airflow**, improving energy efficiency.
- Enhances **indoor air quality**, reducing allergens and pollutants.
Step-by-Step: How to Measure Your Air Filter
1. Check Your Current Filter (But Don’t Rely on It!)
Most air filters have their dimensions printed on the side, but these are often **rounded numbers**, not the actual size. It’s always best to measure it yourself.
2. Measure the Exact Dimensions
Grab a tape measure and follow these steps:
- Measure the length (L), width (W), and thickness (T) in inches.
- Round up to the nearest **1/8 inch** (filters are sold in standard sizes, so rounding helps match the closest available option).
3. Understand "Nominal" vs. "Actual" Size
The **nominal size** is the rounded measurement listed on the filter packaging, while the **actual size** is what you measured.
Example: If your filter measures **19.5” x 24.5” x 0.75”**, the nominal size will likely be **20” x 25” x 1”**.
Popular Air Filter Sizes
Shop our most popular filter sizes below:
Get the Right Fit with Design Filters!
Finding the right air filter size shouldn’t be a guessing game! At Design Filters, we provide high-quality, **precision-cut air filters** for every home and HVAC system. Whether you need a standard size or a custom fit, we've got the perfect filter for you.
Order Your Air Filter Today!
Now that you know how to measure your filter correctly, it’s time to get the right one! Click here to shop all air filters and find the perfect fit for your home. Need help? Contact us here and our team will assist you!