Admit it, you've tugged at the band around your bra, you've readjusted the cups and you've slyly tried to slide a slipping bra strap back onto your shoulder.

Don't be embarrassed, ladies, you're not alone. According to Bare Necessities, about 80 percent of women are wearing the wrong size bra.

Even if you once had the perfect-fitting bra, chances are it needs to be updated. According to MyIntimacy.com, the average woman's breasts change shape, size and distribution more than six times in her lifetime due to factors such as weight loss, weight gain, amount of exercise, childbirth and medications.

If you think it's time you got a bra that fits right, and to give yourself a comfy fit and a more flattering look, follow these tips to find the right-sized bra for you.

First up, size does really matter ...

measuring bra size

No. 5: Size yourself up
When it comes to finding a bra, you can't just eye up the undergarment to see if it's the right size. Finding the right bra requires measuring to determine your bust and band size.

To determine your band size, slip the measuring tape under your arms, across the high section of your back and over the top of your chest, above your bust. According to Bare Necessities, if your measurement is an odd number, add 1 inch. Otherwise, this measurement is your band size.

To determine your cup size, Bare Necessities recommends measuring loosely around the fullest part of your bust. Then subtract your bust size from your band size, and use that number to determine what your cup size is by looking at a size conversation chart. For example, a difference of 2 inches would be a B cup.

Once you find the right size, it's time to look for the type of bra that fits you best ...

bras hanging on clothes line

No. 4: Avoid spillage

When trying on a bra, make sure your breasts are properly contained inside of the undergarment.

Bare Necessities recommends that you look at the front of the bra to ensure there isn't any breast tissue spilling out the front or the sides of the bra, and no skin sneaking out the bottom of the cups. If your tissue is creeping out, then the cup size is likely too small.

In contrast, Susan Nethero of Intimacy stores told Oprah.com that if there are dimples in the bra material then the cup size is probably too large and you should consider trying a smaller size.

She should know too: Nethero trained under the Queen of England's royal bra fitter and has earned the nickname "bra whisperer."

Once you find the right-fitting cup, you are only halfway there to finding the right bra. Next up -- finding a bra with the right-sized band ...

bra straps woman's back

No. 3: Banish back fat

Instead of tugging at your bra or wearing loose-fitting shirts to cover up the dreaded back fat that's hanging out along the edges of your bra, there is an easier solution -- buy a bra with a smaller band size.

According to Nethero, most women think that back-fat sightings mean that the band of their bra is too small. However, it actually means that the band is too big.

Nethero told Oprah.com that getting a smaller band size and wearing the bra lower on your back should eliminate back fat. She added that your bra band should be level front to back.

One fitting suggestion Nethero recommends is when trying on a bra, make sure it fits you correctly on the loosest hook. Then, as the bra becomes older and stretches out, you can tighten it to the second and third hooks to keep a snug fit.

Once you find the right-fitting bra, buy a couple of them so you don't have to worry about wearing them out ...

colorful bras underwear lingerie