Will My Lab Coat Shrink in the Wash? What the Fabric Spec Says

Every cotton-blend garment in history has shrunk on somebody, so the worry is fair. The difference with a proper lab coat is that the answer isn't "maybe" — it's printed in the fabric specification. Here's what ours says, and what it means for how you wash yours.

The Spec Sheet Answer

Our lab coats are 220gsm ±5%, 65% polyester / 35% cotton, with a certified dimensional stability to washing of 3% maximum. That last number is the one that answers this question: it's a textile standard that measures how much a fabric is allowed to change size after laundering, tested under controlled conditions. "3% maximum" means the coat is engineered to shrink by no more than 3% through its wash cycle.

In real terms: 3% on a coat that falls to your knees is around 1.5cm of length — a fraction of a size step, not a size down. The poly in the blend is doing most of that work: polyester doesn't shrink, so a 65/35 blend holds its shape far better than the 100% cotton coats that gave lab coat shrinkage its reputation.

How to Stay Inside the Spec

The 3% guarantee assumes the coat is washed the way the care label says. The ways people blow through it:

• Cooking it in a hot dryer cycle after every wash — repeated high heat is the single biggest driver of shrinkage (and of press-stud and seam wear). Air dry when you can; low heat when you can't
• Washing hotter than the care label allows — "hot wash after contamination" means the hottest the care label permits, not the machine's maximum
• Leaving it bunched wet in a basket — a poly-cotton that dries flat or hung keeps its shape better than one that dries creased and compressed

The full wash routine is in our washing guide.

If You Need to Grow the Coat Back

Did shrink anyway (hot dryer, we're looking at you)? Two fixes:

1. Soak the coat in lukewarm water with a cap of hair conditioner or fabric softener substitute for 30 minutes, then gently stretch the fabric lengthwise while damp, and air dry flat. It won't return to spec, but it recovers a meaningful part of a hot-dryer shrink
2. Accept the size change and reassess — if the coat now pulls across the chest or rides above the knee, it's the wrong coat. At $24 ex GST, replacing beats fighting a garment that no longer covers you properly. See our replacement guide

Sizing With Shrinkage In Mind

The smart move is to never be on the edge of a size. Our Sizing Chart works from a garment you own, flat-measured — pick the size that fits your measurement with room to spare, not the one that just makes it. Within the 3% spec that's irrelevant; outside it (hot dryers), it's the difference between "slightly snug" and "unwearable." Our fit guide covers how much room a lab coat should actually give you.

The Short Answer

No — not meaningfully, if you follow the care label. The fabric is certified to 3% maximum dimensional change, roughly 1.5cm on coat length. The only way to beat that number is sustained hot-dryer abuse, and even that is survivable once. Buy the right size off the chart and wash it sensibly, and shrinkage is a non-issue for the life of the coat.

Shop Coats That Hold Their Shape

Lab coats from $24 ex GST — 220gsm 65/35 poly-cotton, dimensional stability 3% maximum, XXS to 3XL.