If you buy a suit off the rack, there's really only one part that MUST fit perfectly

There are two ways to buy a suit.

One is to have it custom made for your body, which is the ideal way to get the perfect fit but also an expensive option.

The other way is to buy it off the rack, which is affordable but also potentially a risky move.

If you choose to go with the latter, there is one thing you really must know.

The suit has to fit on one crucial part of your body, according to Jessica Cadmus, founder of The Wardrobe Whisperer. Her company coordinates closets for high-powered executives and other professionals.

“When attempting to discern your proper suit size, the most important thing to do is slip on the jacket to ensure best fit in the shoulders,” she said in an email to Business Insider.

You can then take your suit to a tailor and have it shaped. That’s how you make an off the rack suit look hundreds of dollars more expensive. But first, the shoulders need to be right.

“Everything else can be tweaked but the shoulders need to be perfect.”

Now here’s how you make sure the shoulders are perfect.

  • Let your arms rest at your side and have your shopping companion or tailor stand behind you.
  • Have them put their hands at the outer edges of the jackets’ shoulders.
  • If the shoulder seam lines up with the end of your own shoulder, you are golden. If not, adjust up or down a size.

Cadmus says that her first-time customers tend to wear suits that are too big for them because they think it’s more comfortable. Watch out for that.

Also, if you’re over six foot tall and you’re buying a suit, buy a long. If you’re 5′ 6” or less, go with a short.

And be honest with yourself for Pete’s sake.

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