What Size Filter Do I Need for My Lens?

The filter size for your lens is the diameter number printed on the front of the barrel, next to a small ø mark — ø49, ø62, ø77. Buy that millimetre and nothing else. If the ring on your lens reads ø62, the filter you order is 62mm.

That is the whole answer. The rest of this page is the exceptions, because wrong-size orders almost never come from people who cannot read a number. They come from people reading the wrong number, or reading a name instead.

I'm Leo Liang. I run XT Filters, and the size question is the one I answer most in email. My own kit is a Panasonic GH7 with the OM System 12-40mm f/2.8 PRO II — a 62mm front — and I still look at the printed mark before I order glass for it. Muscle memory lies about numbers. The paint on the ring does not.

Where the number is printed

Three places, in the order I'd check them:

1. The front ring, around the glass. It usually reads ø62, or just 62mm, beside the filter symbol. Take the hood off if it covers the mark; some barrels print the size under the hood mount.
2. The back of the lens cap. A few brands stamp the diameter there.
3. The lens's official spec page. Search the exact model and look for "filter diameter" or "filter size" — not the headline specs.

If you cannot find it, or the print has worn off, send us the model. Our lens filter finder looks it up across 893 lenses from 18 brands, and if yours is not in there, email me and I will match it by hand. One thing not to do: measure the front glass with a ruler. The visible element is smaller than the thread, so you will order a ring that is too small. If you are not sure where the mark sits, how to read the filter size on your lens goes through the same ground slowly.

The "35mm" on the barrel is not the size

Focal length and thread size are different numbers that sometimes look the same. A 35mm lens can take a 43mm, 52mm, or 77mm front depending on the design. A 24-70mm zoom does not take 24mm or 70mm either — the Canon RF 24-70mm f/2.8L takes 82mm. Sensor format does not set it either: M43, APS-C and full-frame all use the same millimetre labels once you are buying screw-in glass.

Same lens name, different thread

This is what trips up experienced shooters, because they trust the name on the box and skip the print.

• Nikon Z 24-70mm f/2.8 S takes 82mm; the newer S II takes 77mm.
• Fujifilm XF 16-55mm f/2.8: the original takes 77mm, the II takes 72mm.
• Canon RF 85mm: the f/1.2L is 82mm, the f/2 Macro is 67mm.
• Canon RF 24-105mm is three lenses in one name — 77mm, 82mm and 67mm depending on version; I unpacked that one in its own post.

So the model name alone is not enough. You need the exact version, which is why the printed ring beats the spec page, and both of them beat a forum post.

Sizes that come up most

Grouped by the number, because the number is what you are here for. All of these are from our lookup:

A pattern sits in that list: the full-frame f/2.8 standard zooms cluster at 82mm, a lot of f/1.8 and f/2 primes land at 67mm, and 49mm is the compact-prime thread. Useful as a sanity check, useless as a way to order. Two lenses with the same focal length on the same mount can still differ, so confirm the ø on the actual barrel in your hand.

Cameras with a fixed lens

Some popular bodies do not have a removable lens, and the size question changes shape:

• Leica Q3 / Q3 43: the factory thread is 49mm and screws straight on. We covered it in the Q3 49mm note.
• Fujifilm X100 / X100V / X100VI: there is nothing to mount until the adapter ring goes on; after that it is 49mm, not 39mm. The X100 thread post explains the adapter.

The finder is built for interchangeable lenses, so if you shoot a fixed-lens compact and the number is not obvious, ask before you buy.

Buy the millimetre, then pick the job

Once you have the number, the filter type is a separate decision. Where our line sits:

• Clear protection: the XT996H spans 37–105mm; the XT996S covers 39–82mm.
• Circular polarizer: the XT001 PRO runs 43–95mm; the XT003 covers 39–82mm.
• Black mist 1/4: the XT925 runs 39–112mm; the XT888 Bottom 1/4 covers 39–105mm.

Rangefinder shooters with 34mm and 39mm threads are covered too — Leica and Fuji 39mm sit in the XT996 PRO line.

Find the ø first. Then buy that millimetre in the filter that does the job you actually want. If you would rather not hunt the barrel, the lens filter finder takes your lens and returns the size, and the size guide walks the same ground in pictures.

— Leo Liang