Best Charcoal Filters for Kitchen Compost Bins
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A countertop compost bin with a charcoal filter needs a replacement filter that fits the lid, and a filter that is the wrong size lets odor escape around its edge. The two packs below are the replacement filters we opened on 2026-10-18 for kitchen compost bins. They differ in shape, size and thickness, so measure your bin lid before you order. The sections below explain how to match the filter, how often to replace it, and what the listings do and do not claim.
At a glance: the two filters compared
| Filter | Pack | Shape/size | Thickness | Replacement interval |
|---|---|---|---|---|
| RED FACTOR 8 Pack | 8 (4 round + 4 square) | Round ~6.5 in; square ~4.5 in per side; can be cut to size | 0.4 in (10 mm) — about double the MOWPOG | At least 3-4 months per listing (shorten in hot weather per extension advice) |
| MOWPOG 6 Pack | 6 | Round only, 6.7 x 6.7 in | 0.2 in | Not stated |
Figures are exactly as stated in each listing, checked 2026-10-18. The RED FACTOR listing says not to rinse or wash the filters, which conflicts with general extension advice to wash more often in hot weather — follow the manufacturer’s instructions for the specific filter you buy rather than mixing the two sources’ advice.
Quick answer
If your bin has a round lid about 6.7 inches across, the MOWPOG six-pack is the simplest match. If your lid is square or mixed, or you want both shapes, the RED FACTOR eight-pack includes four round and four square filters. The RED FACTOR listing says the filters are thicker, and the MOWPOG listing says they are thinner, so compare the bin’s filter slot before ordering.
The picks
1. RED FACTOR 8 Pack Extra Thick Charcoal Filters (4 Round, 4 Square): best for mixed lid shapes
Specs (from the listing, checked 2026-10-18): 8 filters, 4 round at about 6.5 inches across and 4 square at about 4.5 inches per side; 0.4 inch (10 mm) thick; felt with activated charcoal; the listing says the filters can be cut to size with scissors; model KCBF-4S4R-10MM.
Replacement interval: the listing says each filter lasts at least 3 to 4 months. A university extension Q&A on compost odor advises changing charcoal more often in hot weather than a product interval suggests, so use the shorter interval in summer.
Pros: two shapes in one pack; the listing gives thickness and a size for each shape. Cons: the listing says do not rinse or wash, which conflicts with the extension advice to wash more often in heat; the listing does not name the bin models it fits.
Best for: a bin whose lid shape you have not yet measured, or a household that uses both round and square containers. Skip if: your bin takes only a 6.7-inch round filter.
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2. MOWPOG 6 Pack 6.7 Inch Charcoal Filter: best for a round countertop lid
Specs (from the listing, checked 2026-10-18): 6 round filters; 6.7 x 6.7 x 0.2 in; activated charcoal; the listing gives a capacity of 3 ounces per filter; the listing says it fits most round lids on compost bins and trash cans; model “Charcoal Filter”.
Pros: one shape and size, which is easy to match; six filters per pack. Cons: at 0.2 inch thick it is about half the thickness of the RED FACTOR filters; the listing does not give a service life.
Best for: a round 6.7-inch lid. Skip if: you need a square filter or the thicker felt.
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How to choose
Measure the filter slot or lid before you buy. For example, a 6.7-inch filter on a 6.5-inch lid will not seat properly, and the RED FACTOR listing says its filters can be trimmed with scissors to fit. Round filters in these listings are 6.5 to 6.7 inches. Square filters in the RED FACTOR pack are about 4.5 inches per side. A filter that is too small will leave a gap, and a gap lets odor out.
Think about thickness. The RED FACTOR listing gives 10 mm, and the MOWPOG listing gives 0.2 inch, about 5 mm. The RED FACTOR listing says the thicker filter is meant to keep smell from escaping, but neither listing gives a test result for odor control or service life. Treat the 3-to-4-month interval as the manufacturer’s claim.
Plan the replacement. Keep a spare pack in the cupboard, and change the filter on the calendar, not when the smell arrives. The extension advice is that heat speeds up odor, so a summer schedule should be shorter than a winter one.
Related guides
For a bin you can build yourself, read Best DIY Compost Bin from a 5-Gallon Bucket. For a trash-can compost option, see Best Compost Bin DIY Trash Can. For starting a bin in the yard, read Best Way to Start a Compost Bin.
Frequently asked questions
How often should I replace a charcoal filter?
The RED FACTOR listing says each filter lasts at least 3 to 4 months. A university extension Q&A on compost charcoal advises changing it more often in hot weather.
Can I wash the filter?
The RED FACTOR listing says not to rinse or wash the filters. The extension Q&A says washing more often in hot weather can help. These two sources conflict, so follow the product’s instructions and replace the filter on schedule.
Will one size fit every bin?
No. The round filters in these listings are 6.5 to 6.7 inches. Measure your bin’s filter slot. The RED FACTOR listing says the filters can be trimmed with scissors if they are too large.
Do charcoal filters stop all compost smells?
No. The extension Q&A also advises lining a bin with paper, because a sealed lid can cause fermentation and odor. Use the filter together with a good lid and regular emptying.
Our decision rule
If your lid is round and 6.7 inches, choose the MOWPOG six-pack. If you need square filters or want both shapes, choose the RED FACTOR eight-pack, and replace it every 3 months in summer.
