What Size Filter Do I Need for My Camera Lens? (Simple Step-by-Step Guide)

Choosing the wrong filter size is one of the most common frustrations for photographers and videographers. The good news is that finding the correct size is extremely easy once you know where to look.

In this guide, you’ll learn exactly how to find your lens filter size quickly and confidently so you can buy the right filters the first time.

Step 1: Check the Front of Your Lens (Easiest & Fastest Way)

Turn your lens around and look at the front barrel, near the glass element. You will see a marking similar to this:

⌀58mm Ø67mm 77mm

• The ⌀ or Ø symbol stands for diameter.
• The number that follows (58, 67, 72, 77, 82, etc.) is your filter thread size in millimeters.

This is the exact number you need to order. Simply buy a filter with the same size and it will screw on perfectly.

Step 2: Still Not Sure? Use These Methods

• Check the original lens cap — the size is often printed on the side or inside.
• Look in your lens user manual or specifications.
• Google your lens model + “filter size” (example: “Sony 24-70mm filter size”).
• As a last option, gently measure the inside of the filter threads with a ruler or digital caliper.

Important Tip: Different lenses on the same camera usually require different filter sizes. Always check each lens individually.

Most Common Camera Lens Filter Sizes

Pro Tips for Buying Filters

• Always match the exact filter size for the best optical performance. Using the correct thread size keeps the filter as close as possible to the lens element. This helps prevent vignetting (dark corners), light leaks, and unwanted flare while delivering sharper, cleaner results.
• Step-up rings save you money: Buy high-quality Freewell filters in your largest lens size and use step-up rings for your smaller lenses. This way you only need one set of premium filters instead of buying multiple sizes.

Recommended approach: If budget allows, always go with the exact size for your most important lenses. For the rest, step-up rings are a smart and cost-effective solution.

Ready to Buy the Right Filters?

Now that you know your filter size, you can shop with confidence.

At Freewell Gear, we design professional ND filters, variable NDs, polarizers, and magnetic filter systems in all popular sizes. Our filters are built tough, color-accurate, and made for real-world filmmaking and photography.

Next Step: Grab your camera, check the ⌀ number on your lens right now, and search for filters in that exact size.

Have a specific lens model? Fell free to contact our customer support and we’ll tell you the exact filter size you need.

Happy shooting — and never guess your filter size again!

Frequently Asked Questions

Q: Can I use a larger filter on a smaller lens? Yes — with step-up/Base Ring rings. This is actually recommended.

Q: Can I use a smaller filter on a larger lens? No. It will cause vignetting (dark corners).

Q: Does filter thickness matter? Yes, especially on wide-angle lenses (24mm or wider). Thicker filters can cause vignetting.

Q: How do I know which Freewell filter size to buy? Just match the ⌀ number on your lens. We carry all popular sizes.