Bras are a wardrobe staple that women (typically) wear every single day. They are also the one item we neglect the most.

Chances are, you probably haven’t had a proper bra fitting since you brought your very first bra. In fact, most women are wearing the wrong size without even realizing it. The wrong bra doesn’t necessarily prohibit you from living your life, but it can hinder it a bit, like lingering dull pain. Ask yourself, are you constantly tugging at your straps? Do you have deep marks in your skin at the end of the day? Or do you simply feel uncomfortable? Or, worse, unsupported? If the answer is yes to any of these questions, then you’re probably in the wrong bra.

The number one cause of ill-fitting bras is age. On average, bras have a lifespan of 6 months to 1 year, depending on wear and care. So, if you’re wearing a bra that’s over a year old, it’s probably not fitting properly. Other signs that your bra is the wrong size: Wrinkling in the cups, underwire poking the sides of your breasts, a band that rides up, cup spillage, slipping straps, or a bra that hikes up when you lift your arms.

So, what do you do once you’ve established that you’re wearing the wrong bra?

First, either get measured by a lingerie professional or measure yourself and consult a brand’s size charts when shopping. Getting fitted can be awkward, and you need to feel comfortable with the right store/company. It’s probably more convenient and quicker to size yourself at home, so bust out your tape measure and follow these steps.

First, wear your most comfortable, lightly lined, non-push up bra. Then measure your band by wrapping a measuring tape directly under your breasts. Make sure it’s directly parallel with the bottom of the bra band. Then note the number of inches and round down to the nearest even number. Second, measure your bust by placing the tape around the fullest part of your bust, making sure it’s parallel to your band again. Then subtract the band size from your bust size to find the right cup size. Every inch equals one cup size up. So, if the difference between your band and bust size is 1 inch, you’re an A cup, 2 inches a B cup, 3 inches a C cup, etc. Of course, cup size can vary from brand to brand, so be sure to consult the chart.

Once you have your size and found bras you like, whether online or in the store, the work is not over just yet. For the best fit, bend forward at the waist, then slip on the bra and hook it. This ensures your breasts are completely in the cups. Adjust the band as needed — the back of the bra should be level with the front. To make sure the bra is not too loose, you should be able to slide only one finger underneath the band. Shorten the straps if they are falling off your shoulders.

To see if your bra not only feels good but also looks good, start with the outermost hook and try it on with a close-fitting shirt. If the cups pucker or your breasts bulge, you’re not wearing the correct size. Look at yourself sideways in a mirror. Your breasts should sit midway between your shoulders and elbows. If not, you need a more supportive and better-fitting bra. If you need to go down a cup size for fit, go up one band size and vice versa. Also, try on a button-down shirt to see if there’s any button gappage.

Once you have your fit down, and find bras that suit you, don’t feel you need to measure or get professionally measured whenever you refresh your brassiere selection. However, keep in mind that certain factors can cause a change in size. Things like weight gain, or loss, a new exercise regimen, pregnancy, and change in diet can affect your bra size.

If you experience any of these types of lifestyle changes, then it’s time to get refitted and get new bras.