How to Sort Laundry the Right Way
Most people sort laundry by size, a habit that feels intuitive but actually works against you: the American Cleaning Institute's real guidance is built around color, soil level, and fabric type, and it explicitly recommends mixing small and large items together in the same load.
Key takeaways
- Sort by color (whites, mediums/pastels, brights/darks), not by weight.
- Mix small and large items in the same load — ACI recommends it for better tumbling action.
- Keep heavily soiled items separate from lightly soiled ones to prevent graying and dye redeposit.
- Keep 'lint loser' fabrics (fleece, chenille, new towels) away from 'lint collector' fabrics (corduroy, permanent press).
- The care label overrides any general sorting rule — check it before adding an item to a load.
Sort by Color First
Split loads into three color groups: whites on their own, pastels and medium colors together, and brights or darks in their own load.
- White and light-colored synthetics need extra caution — they pick up dark dye more readily than natural fibers, so don't wash a white polyester shirt with a load of dark cottons.
- Fluorescent and neon items are often not colorfast. Wash them separately, or test a hidden seam first.
- Check trims, linings, and embellishments before assuming an item belongs with its main color — a trim dyed differently can bleed even when the garment itself is safe.
Always check the care label before grouping an item into a load — some pieces need to be washed alone or by hand regardless of color.
Separate by Soil Level
Heavily soiled items and lightly soiled items don't belong in the same load. Soil and dye that comes off a dirty item redeposits onto cleaner ones — whites gray or yellow, and colors dull. If a few pieces are visibly dirtier than the rest of the wash, hold them for their own load, or pretreat them and wash them last.
Watch Fabric Type and Lint
Delicates and loose knits need gentle handling and shouldn't be washed with heavier, rougher fabrics that can snag or stretch them.
Lint is its own sorting problem. Some fabrics are lint losers — they shed fuzz in the wash — and others are lint collectors — they attract and hold onto whatever lint is floating around:
- Lint losers: fuzzy sweatshirts, chenille, flannel, and new towels
- Lint collectors: corduroy, permanent-press fabrics, and other napped materials
Keep losers and collectors apart, or you'll pull a corduroy jacket out of the wash covered in towel fuzz.
The 'Sort by Weight' Myth
Sorting by weight — putting all the heavy items in one load and all the light items in another — is common advice, but it isn't what the American Cleaning Institute actually recommends. ACI's guidance runs the other way: mix small and large items together in the same load (an 'unmatched set') so clothes have room to move and tumble freely against each other. That movement is part of what gets a load clean. A load of all-heavy or all-light items doesn't tumble the same way, and can wash less effectively than a genuinely mixed load.