Coffee filter numbers are only useful after you identify the filter system. A Melitta-style #4, a Hario V60 02, a CHEMEX bonded filter and a Standard AeroPress disc belong to four different families. Their numbers do not translate across brands.
Check the brewer’s exact model or manual first. If that information is missing, match the basket shape and test one unused filter while everything is dry. The paper should reach the basket walls without leaving gaps, bunching heavily or folding over the rim.
The filter system matters before the size number
Filter packages often place a large number on the front, but the brewer family carries more information than the number. Start by looking into the empty brewer.
| Brewer family | What to match | Common mistake |
|---|---|---|
| Melitta-style cone | Brewer model and the specified #1, #2, #4 or #6 paper | Choosing from “cups” without checking the model |
| Hario V60 | 01, 02 or 03 printed on the dripper | Treating V60 02 as equivalent to Melitta #2 |
| CHEMEX | Brewer size and the official folded, circle or half-moon format | Buying a generic cone paper by visual similarity |
| AeroPress | Standard or XL diameter | Assuming all round AeroPress papers are the same |
| Basket brewer | Basket style, bottom diameter, top opening and wall height | Looking for a cone number on a flat-bottom package |
Round paper does not automatically mean AeroPress. A folded cone does not automatically mean CHEMEX. Even within one broad shape, the wall angle, height and bottom width can change. The safest purchase is the filter format named by the manufacturer for the exact brewer.
What #1, #2, #4 and #6 coffee filters mean
Within the current Melitta cone line, the number generally increases with paper size. The official fit statements are more useful than trying to memorize dimensions from an unverified chart.
| Melitta cone size | Current official fit statement | Practical reading |
|---|---|---|
| #1 | 1-cup electric cone coffeemakers | The smallest numbered paper in this group |
| #2 | 2–6 cup electric and 1-cup non-electric cone coffeemakers | Shorter than #4; common in small cone brewers |
| #4 | 8–12 cup cone coffeemakers | A common household automatic-cone size |
| #6 | 10-cup non-electric cone coffeemakers | A larger paper for specific manual cone brewers |
Cup count is a clue, not a universal rule. Melitta's own 1-Cup Pour-Over product page says that brewer can use #2 or #4 paper. Its 42 oz thermal pour-over set specifies #4, while the 52 oz glass carafe set specifies #6. Those examples are why the model page or manual beats a chart based only on servings.
Two papers can share a cone shape and still differ in height, wall angle and bottom width.
Four checks for choosing a coffee filter
- Check the basket shape. Decide whether the brewer uses a pointed cone, truncated cone, flat-bottom basket, folded CHEMEX paper or round AeroPress disc.
- Find the exact brewer model. Read the label under the machine, the dripper marking, the manual or the manufacturer's current product page.
- Match the filter system. Use Melitta #4, V60 02, AeroPress Standard or another name only inside the system that printed it.
- Test the dry fit. Place one unused paper in the empty basket. Check the wall contact, rim height and folds before adding coffee.
Do not trim the rim, tear the seam or crush a nearby-looking paper into the basket. Those fixes change how the paper sits and can leave a bypass path for water or grounds. If the paper is clearly wrong while dry, return to the model number and package fit list.
V60 01, 02 and 03 use matching V60 paper
Hario uses 01, 02 and 03 as V60 size names. The current Hario USA pages describe 01 paper as 1–2 cups, 02 as 1–4 cups and 03 as 1–6 cups. More useful than the serving range is the direct pairing: 01 paper for a V60 01 dripper, 02 paper for a V60 02, and 03 paper for a V60 03.
A V60 02 is not Melitta #2. The zero is part of Hario's size name, and the paper is shaped for the V60 dripper. If the size marking has worn off, compare the brewer model or product code rather than guessing from the top diameter.
CHEMEX filters depend on the brewer format
CHEMEX uses proprietary bonded papers in several shapes. The official half-moon page names item codes FP-2 and FP-2N for the 3-cup CHEMEX and Funnex. Larger classic brewers use the bonded filter formats listed for those models, including pre-folded circles and squares.
The 3-cup brewer is the common trap. Its half-moon paper is not a smaller version of the full-size pre-folded square. Check whether the package names the 3-cup model or Funnex before opening it.
AeroPress Standard and XL filters are different sizes
Current Standard AeroPress paper fits Original, Clear, Premium, Steel, Go and Go Plus. AeroPress XL uses a separate XL paper and filter cap. The official XL page says the XL papers are not compatible with the Standard-size brewers.
If you are deciding between paper and a reusable metal disc after confirming the diameter, see our AeroPress paper vs metal filter guide. Filter material changes clarity, body and cleanup, but it does not remove the need to match Standard or XL.
Basket filters and the dry-fit check
Flat-bottom basket papers are usually sold by a cup range or physical dimensions rather than Melitta cone numbers. Read the brewer manual first. If the model is old and the manual is unavailable, measure the empty basket at three points: bottom diameter, top opening and wall height.
A paper that is too small can leave part of the basket wall exposed. A paper that is too large may bunch, fold into the coffee bed or sit above the basket rim. Wet paper can cling and hide the mismatch, so make the first check while the basket and paper are dry.
If the dry paper sits neatly, you have solved the size question before sacrificing a brew.
Frequently asked questions
Which coffee filter is bigger, #2 or #4?
A #4 coffee filter is generally taller and larger than a #2 within the Melitta-style cone system. Melitta currently lists #2 for 2–6 cup electric and 1-cup non-electric cone brewers, while #4 is listed for 8–12 cup cone coffeemakers. Check the exact brewer because some manual cones accept more than one paper size.
What is the difference between a #4 and a #6 coffee filter?
Both are numbered cone papers in the Melitta system, but #6 is the larger format. Melitta lists #4 for 8–12 cup cone coffeemakers and #6 for 10-cup non-electric cone coffeemakers. The overlapping serving labels are another reason to follow the brewer model rather than choose by cup count alone.
Can I use a #4 filter instead of a #2?
Only when the brewer instructions allow it. Melitta's current 1-Cup Pour-Over page says that model can use #2 or #4 paper, but that does not make the sizes interchangeable in every cone brewer. Dry-fit the paper and follow the model's manual or official product page.
What filter size does a 12-cup coffee maker use?
A 12-cup label does not identify the basket shape. A Melitta-style 8–12 cup cone machine commonly uses #4 paper, while a 12-cup flat-bottom machine needs a basket filter. Check the brewer model and look inside the empty basket before buying.
Are V60 02 and #2 coffee filters the same?
No. V60 02 is Hario's size for a matching V60 02 dripper. Melitta #2 belongs to a different cone-filter system. The papers can differ in height, angle and seam geometry even when both packages display the number two.