How to Fix a Stretched, Shrunken or Snagged Sweater

Most knitwear damage is reversible. A stretched knit is reshaped damp and dried flat. A shrunken one is relaxed in cool water with conditioner and stretched back. A snag is pulled through to the inside with a needle — never cut. Only felted wool is genuinely permanent.

Knitted fabric is loops, and loops can usually be persuaded back into position. That is the reason so much knitwear damage can be undone — and also the reason it happens in the first place.

A stretched knit

Usually fixable · 30 minutes plus drying

Nearly always caused by hanging a wet knit, where the weight of the water pulls the shoulders down and out.

Wash the garment in cool water, by hand or on a gentle cycle. Wetting the fibres is what allows them to relax and reset.
Press the water out. Never wring. Roll in a towel and press.
Lay it flat and reshape it to the measurements it should be, using another garment of the same size as a guide if you have one.
Pat the shoulders, cuffs and hem into place specifically. These are where distortion concentrates.
Dry completely flat, away from sun, turning once.

Cotton and cotton-rich blends usually recover well. Wool recovers best of all. If the fibres have been stretched past their elastic limit, this improves the shape without fully restoring it.

A shrunken knit

Often fixable · Depends entirely on the fibre

Fill a basin with cool water and add a capful of hair conditioner or a little wool detergent. This relaxes the fibres and lets them slide.
Soak for 15 to 20 minutes.
Press out the water without rinsing thoroughly — a little residue helps the fibres move.
Lay flat and gently stretch back towards the original dimensions, working evenly across the whole garment rather than pulling at one spot.
Pin to a towel to hold shape if needed, and dry flat.

The exception: felted wool. When wool is exposed to heat and agitation, the microscopic scales on each fibre interlock permanently. That is felting, and it is a physical change rather than a stretch. No treatment reverses it. Cotton does not felt, which is why cotton knits are far more recoverable.

A snag or pulled thread

Almost always fixable · Two minutes

The instinct is to cut the loop. Do not. In knitted fabric every loop is holding the next one, so cutting creates a hole that will run.

Turn the garment inside out and find the snag.
Thread a blunt needle or use a snag-repair tool.
Push the needle through from the inside at the base of the pulled loop.
Hook the loop and draw it through to the inside of the garment.
From the right side, gently stretch the fabric around the area in both directions. The gathered yarn redistributes and the pucker disappears.

If the snag is long, work the excess yarn back gradually along the row rather than pulling it through in one go.

Yarn and knitted swatch showing the interlocking loop structure — Every loop holds the next. That is why a snag can be worked back in — and why cutting one creates a hole that runs.

Yarn cones showing the continuous yarn a knit is made from — Every loop holds the next. That is why a snag can be worked back in — and why cutting one creates a hole that runs.

Stretched cuffs and hems

Sometimes fixable · Worth trying

Ribbing loses recovery before the rest of a garment does, because it takes the most stress.

For natural fibres, dampen the ribbing with warm — not hot — water, then squeeze it gently into its correct width and let it dry flat in that shape. Some elasticity returns.

If the rib was under-tensioned when the garment was made, this will not hold. That is a construction fault rather than wear, and it is why checking ribbing recovery before buying matters.

A small hole

Fixable · Act quickly

A hole in knitted fabric will run if left, because each dropped loop releases the one below it. Deal with it the day you notice it.

For a small hole, thread matching yarn onto a needle and use duplicate stitch — following the path of the existing stitches rather than sewing across the gap. This rebuilds the knit structure instead of patching over it, and done carefully it is close to invisible.

For anything larger than a few stitches, a specialist invisible mender is worth the cost on a good garment.

What is fixable, and what is not

Problem	Outlook	Method
Stretched body or shoulders	Usually fixable	Wash cool, reshape damp, dry flat
Shrunken cotton or cotton blend	Often fixable	Conditioner soak, stretch damp
Felted wool	Permanent	None. Fibres have interlocked.
Snag or pulled loop	Almost always fixable	Pull through to inside, redistribute
Pilling	Fixable	Fabric comb, flat surface, one direction
Stretched ribbing	Sometimes	Damp, reshape, dry flat
Small hole	Fixable if caught early	Duplicate stitch with matching yarn
Colour bleed	Rarely	Colour remover, at some risk

Preventing all of it

Never hang a wet knit. This single habit prevents most stretching.
Never wash above 30°C, never tumble dry. This prevents shrinkage and felting.
Fold, do not hang, for storage. Hangers cause slow shoulder distortion.
Remove rings and watches when pulling a knit on. Most snags happen at that moment.
Deal with snags immediately. Two minutes now, or a hole later.

Frequently asked questions

How do you fix a stretched sweater?

Wash it in cool water, press the water out without wringing, then lay it flat and reshape it to the correct measurements while damp. Pay particular attention to the shoulders, cuffs and hem, and dry it completely flat away from direct sun. Cotton, cotton blends and wool all recover to a useful degree.

Can you unshrink a sweater?

Often, yes. Soak it for 15 to 20 minutes in cool water with a capful of hair conditioner, which relaxes the fibres, then press out the water and gently stretch the garment back towards its original dimensions while damp before drying flat. This works on cotton and cotton blends, but felted wool cannot be reversed.

How do you fix a snag in a sweater?

Never cut it. Turn the garment inside out, use a blunt needle or snag tool to hook the pulled loop and draw it through to the inside, then gently stretch the surrounding fabric in both directions so the gathered yarn redistributes. Cutting a loop creates a hole that will run.

Why does my sweater have a hole in it?

Common causes are snags that were cut or left untreated, friction wear at the elbows or underarms, or insect damage during storage. In knitted fabric a dropped loop releases the one below it, so a small hole spreads quickly and should be repaired as soon as it appears.

Can felted wool be reversed?

No. Felting occurs when heat and agitation cause the microscopic scales on wool fibres to interlock permanently. It is a physical change to the fibre structure rather than a stretch, so no soaking or stretching will undo it. Cotton does not felt.

How do you fix stretched cuffs on a sweater?

Dampen the ribbing with warm but not hot water, squeeze it gently into its correct width, and let it dry flat in that shape. Some elasticity returns. If the ribbing was under-tensioned when the garment was made, however, the fix will not hold.

The short version

Stretched: wash cool, reshape damp, dry flat. Shrunken: conditioner soak, stretch damp. Snagged: pull through, never cut. Felted wool: nothing to be done.

Most of this comes back to the same two habits — washing correctly and storing folded. More on removing pilling.