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How to Properly Size Yourself for a Lifejacket

How do you select the right lifejacket for your needs? Here are tips for sizing adults and children for a lifejacket.

How to Properly Size Yourself for a Lifejacket

Whether you’re taking a leisure cruise on the weekend or dashing out for an evening of fishing, safety aboard your boat is always important. That goes beyond your on-the-water knowledge to navigate and having a First Aid kit aboard. You should be prepared for the most unexpected circumstance: accidentally falling overboard.

Lifejackets are devices intended to save lives – it’s literally in their name! Their buoyancy protects you from going under. Whether you’re a seasoned swimmer or you can’t tread water, a proper-fitting lifejacket will keep your head above water if you’re dazed, panicked, or unconscious. It must fit well, though, or it might not provide enough buoyancy, or it could slip off.

How do you select the right lifejacket for your needs? Here are tips for sizing adults and children for a lifejacket.

Lifejacket sizing for adults

For adults, lifejacket sizing is about your body size, although weight may factor into the selection as well. Specifically, it’s your chest size that determines the proper fit for a lifejacket. To measure your chest size as it affects your lifejacket choice, measure the circumference at the widest point on your chest. You’ll need this number as other common sizing methods aren’t standardized.

Find a lifejacket that’s appropriately sized for your chest measurement, but there’s more to fitment than just chest size. The PFD manufacturer has other criteria that you’ll find on the tag or printed on the back of the lifejacket to finetune sizing. There may be a weight capacity listed, and you should never exceed the tested buoyancy.

Fitting a lifejacket should follow these steps to make sure it fits right:

  • With all the straps loosened, put the lifejacket on and fasten it. Pull all the straps snug, whether you’re trying an inflatable PFD or a standard lifejacket. It should feel like a gentle hug but it shouldn’t restrict your breathing.
  • Try the lifejacket on wearing clothing like what you’d usually wear on the water, mimicking real-life usage.
  • While you’re wearing it, have a buddy pull up on the shoulders. A properly fitting lifejacket should not be able to move up past your nose or head while done up.
  • Move around. A properly-sized lifejacket shouldn’t impede the motion you need for the activity you’re using it for, from paddling or casting to waterskiing.

It’s also a great idea to test your chosen lifejacket’s buoyancy in a pool or at the beach before you’re in an emergency scenario. Ensure it holds your weight well and doesn’t slip.

Sizing a lifejacket for a child

For children, lifejacket sizing is different. It’s based on weight across three categories: infant, child, and youth.

  • Infant lifejackets are intended for children between 8 and 30 pounds.
  • Child lifejackets are for those between 30 and 50 pounds.
  • Youth lifejackets are sized for those between 50 and 90 pounds.

Features you’ll typically find on an infant an a child lifejacket are a padded head support that aids in keeping their head above water and an integrated grab handle to pull them from the water if necessary. They’re also equipped with a crotch strap to prevent the child from slipping down out of the lifejacket.

A youth lifejacket is manufactured identically to an adult PFD, except for its intermediate size for smaller bodies. Life jackets are only an effective safety device if they’re worn. Get into the habit of wearing a PFD whenever you’re out on the boat.


A great addition to wearing a lifejacket is the 1st Mate system, and the 1st Mate Fob can clip onto your lifejacket effortlessly with a carabiner. When you hit the water, the fob immediately initiates a man overboard (MOB) alarm and sends a GPS location in-app. If it’s the captain that goes overboard, 1st Mate cuts the engine as well.  

Discover all the features of the 1st Mate safety and security system right here.

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