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Coffee Filter Sizes Explained – #2 Filter vs #4 Explained

by Kieran MacRae | Last Updated: September 25, 2020

Coffee Filter Sizes Explained – Find Out What Filter You Need

If you’re confused about all the different sizes of coffee filters I’m not surprised. I ended up down a rabbit hole trying to find what all the different sizes are.

To the point where I bought a pack of every size just so I could compare!

So if you’re confused as to what filter you might need for your coffee gadget look no further I’ve got a complete rundown of the sizes below starting with the smallest and going to the biggest

Selection of Melitta coffee filters

These are all based on the Melitta coffee filters, they are the original coffee filter and to a lot of people the gold standard. Any other filter using this sizing has based it off Melitta so they will be the same size or only slightly different.

I bought another brand of #4 filter just to check this was the case and it is, there are just a couple of millimeters of difference between the two. Nowhere near enough to affect the taste or how you brew your coffee.

#2 vs #4 Coffee Filter The Differences Explained

These are the two most common filter sizes, and the two that cause the most confusion.

You’ve probably sat looking at all the filters yourself, looking at two near-identical filters except one says it’s a #2 filter and the other says it’s a #4. So what’s the difference?

The difference between a #2 filter and a #4 filter is the size. A #2 filter is made to fit a 2-6 cup coffee machine or a 1-2 cup pour-over and a #4 filter is made to fit an 8-12 cup coffee maker

That’s all, as long as they’re the same brand and they say they’re the same type (likely a cone coffee filter) then you just need to get the right size for you

Can You Use A #4 Filter In a #2 Device or Vice Versa?

The big question isn’t if you can get away with buying them, it’s that you’ve already bought the wrong size and are wondering if you can get away with it, aren’t you?

If you want to use a #4 filter in a #2 size coffee maker you’re going to need to trim it with scissors. Easy enough to do, just put it in your coffee machine and see how much sticks out the top and then cut it down to the right size so the tops are level and you can close the lid.

You can potentially put a smaller filter into a bigger device, you’ll just have to be extra careful when you’re adding your coffee grounds. Depending on the divide you might not get the same coverage of water over your grounds but just try it, it’s worth a shot if you’ve already bought them and can’t return them.

Are #2 and #4 Filters Different Thicknesses?

Nope, they are made the same way, the only difference is the height and the diameter, the actual paper quality is the same and they make the same coffee. If you taste a difference it’s more likely due to the amount of grounds and how the water is poured on them rather than the quality of the filter itself.

1×2 vs #2 vs 102 Coffee Filters?

1×2 is Meilittas name for the #2 filter it means 1 filter for 2 cups of coffee.

There are a confusingly large amount of sizes of filters which seems to all be slightly different, and the 102 is one of them. 102 was the size before coffee machine sizes were somewhat standardized.

The 102 filter is slightly bigger than the #2, it’s not as steep-sided making it wider at the top and it’s not quite as tall.

The 102 filter was originally made before there was a good way to make coffee, they were more or less a random sized coffee filter you could pour your coffee through. A smaller amount of coffee than a 103 or 104 filter.

But now Melitta still has some coffee makers that are a 102 size and that’s what matches up with the 102 filters. The main one being there 102 porcelain filter, I’m honestly not sure why they still make this if it’s such an outdated size to their other products but people must be buying it.

If you asked me a lot of confusion and headaches would be fixed if everyone could agree what size filters would be the most useful but alas without this the world does keep turning.

All three are close enough in size that you could likely get away with using them interchangeably. Always buy the proper recommended size of course but if you wanted to you could.

What size is a standard coffee filter?

If you’ve got a coffee machine and you don’t know what filter to get I can help.


A standard coffee filter is a 2 pint, 8-12 cup, basket filter for a drip coffee machine. And if that doesn’t look right to what you’ve got then you’ll likely want a #4 filter.

If you’ve just bought a coffee machine without too much thought I’d say there’s a 95% chance that you’ve got one of these sizes. Always a chance you didn’t but when I go into people’s houses and have a nose at their coffee set up (because I have to) an 8-12 cup drip machine is normally the first thing I see.

What is the pore size of a coffee filter?

I can’t seem to get a straight answer for this, I found a patent for a coffee filter with a maximum pour size of 20 microns but elsewhere you seem to get a range from anywhere between 15-100 microns.

So very small is the answer but I’m sure that’s not what you came for!

For comparison, a fine mesh strainer has a pour size of around 800 microns, so coffee filters are one of the finest filters you get, smaller than a cheesecloth too.

Final Thoughts

While it can seem confusing (I know I was confused) I hope this helped, and if you’re still confused or you were looking for something else please let me know in the comments and I can help you there.

Related Reading

8 Ways To Make Coffee Without A Filter (2021 Edition)
Brown vs White coffee filters (Bleached or Unbleached)
Are Coffee Filters Compostable? (Everything You Need To Know)
Can You Use Paper Filters With A French Press? You Can But Don’t

Kieran MacRae tried getting into wine but didn't like it, tried getting into whiskey and it was too expensive, then thought "I really love coffee. I wonder if you can get really into coffee?" Turns out you can!