How to Wash Knit Sweaters in Washing Machine

You love your cozy knit sweaters but dread laundry day because you’re afraid they’ll shrink, pill, or lose their shape. You’re not alone. Washing knit sweaters in the washing machine can be safe and effective if you do it right. The good news: most acrylic and even some wool sweaters can go in the wash without damage, as long as you follow the correct steps. In this guide, you’ll learn exactly how to wash knit sweaters in your washing machine safely, avoid common mistakes, and keep your favorites looking new for seasons to come.

Always start by checking the care label. If it says “machine washable,” you’re good to go. If it says “dry clean only” or “hand wash only,” skip the machine. But if it’s approved, follow these steps to protect fibers, prevent shrinking, and maintain softness.

Check the Care Label First

Before tossing any knit sweater into the washer, read the label. This tiny tag holds the key to safe cleaning.

What to Look For on the Label

• “Machine washable”: Safe for washer with proper settings
• “Hand wash only”: Do not machine wash, hand clean instead
• “Dry clean only”: Avoid water entirely, take to a professional
• Wool or cashmere: Often machine-washable if labeled correctly
• Water temperature symbols: A bucket with one dot means cold water only

Ignoring the label is the fastest way to ruin a favorite sweater. When in doubt, hand wash.

Prep the Sweater for Washing

Proper prep protects your sweater from pilling, snagging, and stretching during the wash cycle.

Turn Inside Out or Use a Mesh Bag

• Turn the sweater inside out to shield the outer surface from friction
• Place it in a large mesh laundry bag, ideal for delicate knits and loosely woven fabrics
• For cardigans or zip sweaters, zip up or button closed to prevent snagging

This small step dramatically reduces wear on fibers and keeps your sweater looking smooth.

Choose Cold Water and Delicate Cycle

Using the wrong settings is the number one cause of sweater damage in the machine.

Select These Washer Settings

• Water temperature: COLD. Warm or hot water can shrink wool and damage delicate fibers
• Cycle: DELICATE or WOOL setting. Ensures slow agitation and gentle spinning
• Spin speed: LOW. High spin creates twisted, misshapen sweaters

Never use heavy-duty, normal, or permanent press cycles. These are too harsh for knit fabrics.

Use the Right Detergent

Not all detergents are safe for knitwear. Harsh chemicals can break down fibers and fade colors.

Best Detergent Choices

• Cold-water formula like ARM & HAMMER Deep Clean Stain Formula Liquid Laundry Detergent
• Fragrance-free, hypoallergenic options like ARM & HAMMER Sensitive Skin, Free & Clear
• Avoid bleach and fabric softeners. They weaken fibers and reduce absorbency

Use only a small amount, about a capful, to avoid residue buildup.

Wash With Like Items Only

What you wash with your sweater matters just as much as how you wash it.

Do and Don’t

• Wash with other delicates like silk scarves, lightweight knits, or lingerie
• Keep loads small to reduce crowding and friction
• Don’t wash with jeans, towels, zippers, or heavy fabrics that cause pilling and snags
• Don’t overload the machine. Sweaters need room to move gently

Think of it like packing a suitcase. Too much stuff causes wrinkles and damage.

Remove Promptly After Washing

Leaving a wet sweater sitting in the washer leads to wrinkles, odors, and potential mildew.

Act Fast

• Remove immediately when the cycle ends
• Gently reshape if needed before drying

Do not let it sit, even for an hour. Timely removal keeps fibers aligned and prevents mustiness.

Dry Flat to Maintain Shape

This is non-negotiable: never hang a wet sweater.

How to Dry Knit Sweaters

1. Lay a clean, dry towel on a flat surface
2. Place the sweater on top and reshape to its original dimensions
3. Smooth out sleeves and collar to avoid creases
4. Let air dry away from direct sunlight or heat sources

Hanging stretches shoulders and causes sagging. Drying flat preserves the fit.

Only acrylic sweaters labeled “tumble dry low” should go in the dryer, and even then it’s risky. Heat causes fiber breakdown over time. When in doubt, dry flat.

Prevent Pilling and Fraying

Pilling is unsightly and makes sweaters look old fast. But you can minimize it.

5 Ways to Reduce Pilling

• Always use the delicate cycle. Less agitation means less fiber friction
• Wash less often. Wear three to five times between washes unless soiled
• Avoid mixing with rough fabrics. No jeans, Velcro, or coarse weaves in the same load
• Use cold water only. Hot water weakens fibers and increases pilling
• Invest in a fabric shaver. Gently removes pills from sleeves, underarms, and torso

Prevention beats correction. Small habits extend your sweater’s life.

Deodorize Sweaters from Storage

Pulled a sweater out of storage only to find it smells musty? Do not panic. You can freshen it safely.

How to Remove Musty Odors

• Add one-half cup baking soda to the wash cycle or one-quarter cup to hand-wash water
• Use ARM & HAMMER plus OxiClean Odor Blasters detergent for deep deodorizing
• Try in-wash scent boosters like Clean Scentsations Purifying Waters for a fresh finish

Always inspect for stains first and pretreat if needed. Then follow standard washing steps.

Store sweaters clean and dry with cedar blocks or lavender sachets to prevent odors next season.

Hand Wash When in Doubt

If your sweater is cashmere, fine wool, or unlabeled, skip the machine altogether.

Quick Hand-Wash Steps

1. Fill a basin with cold water
2. Add one-quarter cup gentle detergent and mix
3. Submerge sweater, swish gently, soak ten to fifteen minutes
4. Rinse thoroughly in cold water
5. Press out water with a towel. Never wring
6. Lay flat to dry

It takes just twenty minutes and gives you complete control over the cleaning process.

Common Mistakes to Avoid

Even small errors can ruin a sweater. Steer clear of these pitfalls.

What Not to Do

• Using hot water causes wool to shrink and acrylic to weaken
• Overloading the washer increases friction and pilling
• Skipping the mesh bag causes direct contact with drum or other clothes that damages fibers
• Hanging to dry stretches shoulders and distorts shape. Always lay flat
• Washing too frequently wears out fibers faster

Washing less, washing gently, and drying properly are the golden rules.

Frequently Asked Questions About Washing Knit Sweaters in the Machine

Can you wash all knit sweaters in the washing machine?

No. Always check the care label first. Some sweaters say “dry clean only” or “hand wash only” and should never go in the machine. Most acrylic sweaters are safe, and many wool sweaters can be machine washed if labeled accordingly.

What temperature is safest for washing knit sweaters?

Cold water is the safest choice. Warm or hot water can shrink wool and damage delicate fibers. Look for the cold water symbol on your care label, which often shows as a bucket with one dot.

How do I prevent my sweater from shrinking in the wash?

Use cold water, select the delicate cycle, and avoid high heat when drying. Always lay sweaters flat to dry rather than hanging them. Following the care label instructions is your best defense against shrinking.

Should I use a laundry bag for my sweaters?

Yes. Placing your sweater in a large mesh laundry bag protects it from friction and snagging during the wash cycle. Turning the sweater inside out works similarly and provides the same protection.

How often should I wash my knit sweaters?

You can wash sweaters every three to five wears unless they get stained or visibly dirty. Washing less frequently helps preserve fibers and extends the life of your sweater.

Key Takeaways for Washing Knit Sweaters in the Washing Machine

You can wash knit sweaters in the washing machine safely and effectively if you use cold water, a delicate cycle, and proper preparation. Always read the care label first to confirm machine washing is approved. Turn the sweater inside out or use a mesh laundry bag to prevent pilling and snagging.

Choose a cold-water detergent and wash with other delicates only. Remove the sweater promptly when the cycle ends and lay it flat to dry. Never hang a wet sweater or use hot water. These simple steps ensure your sweaters stay soft, shapely, and pill-free season after season, whether they’re acrylic, merino wool, or wool blends.