How To · Fashion · Essentials
Find Your True Size Across Every Brand
Every brand sizes differently—and that's not your fault. Here's how to establish your baseline measurements and navigate the sizing maze with confidence.
5 min read · IrisYou're a size 8 at one store and a 12 at another. You try on the same style in two colors and one fits like a dream while the other gapes at the shoulders. This isn't a reflection of your body—it's a reflection of how fragmented sizing has become. The solution isn't to blame yourself; it's to know your actual measurements and learn to read what each brand is really offering.
Finding your true size means establishing a personal baseline, understanding how different brands cut their clothes, and developing the skill to predict fit before you buy. It takes about ten minutes and a soft measuring tape. After that, you'll shop with the kind of certainty that makes getting dressed feel less like a gamble.
Your body hasn't changed. The brands have.
What you'll need.
- 01Soft measuring tape (not a ruler)
- 02Notebook or phone notes app
- 03Brand website and size charts
- 04Product reviews (verified purchases)
Step one · 2 minutes
Measure yourself in the right way
Wear a fitted tank or bra—nothing padded or structured. Use a soft measuring tape, not a ruler. Measure your bust at the fullest point (usually across your nipples), your natural waist (the narrowest part when you bend slightly), and your hips at the fullest point. Write these numbers down. Measure twice to confirm. These three measurements are your personal baseline and they don't change when brands do.
Stand in front of a mirror and keep the tape snug but not tight—it should sit flat against your skin without digging in.
Step two · 1 minute
Check the brand's size chart before you buy
Every legitimate brand publishes a size chart. Find it on their website (usually in the footer or near the size selector). Compare your measurements to their chart, not to the size number you usually wear. A brand might list a size 8 as 34–35" bust and 26–27" waist. If your bust is 36", you're between their 8 and 10. This is the information that matters.
Screenshot or bookmark the size charts for brands you buy from regularly. They occasionally change production facilities and update their sizing.
Step three · 2 minutes
Read customer reviews for fit clues
After you've checked the size chart, scroll through customer reviews and look for fit comments. People will tell you if something runs small, large, or true to size. They'll mention if the waist is generous or if the shoulders are narrow. This is crowdsourced fit data and it's invaluable. A review that says 'I'm usually a 10 and sized up to a 12 for comfort' tells you more than any marketing copy.
Filter reviews by verified purchases and look for comments from people with similar body proportions to yours.
Step four · 2 minutes
Understand the difference between size and fit
A size is a number. Fit is how a garment is cut—the proportions of the sleeves, the length of the torso, the width of the shoulders. You might be a true size 10 in bust measurement but need a size 8 in a brand that cuts generously through the waist, or a size 12 in a brand with narrow armholes. Once you've bought from a brand, you know how they cut. Use that knowledge going forward.
Keep one well-fitting piece from each brand you love. Use it as a reference when you're unsure about a new style.
Step five · 2 minutes
Account for fabric and garment type
A fitted cotton blouse will fit differently than a loose linen shirt, even in the same size. Stretchy fabrics forgive fit inconsistencies; rigid fabrics expose them. A wrap dress is cut differently than a shift dress. Once you understand your measurements and a brand's baseline sizing, you can predict how different styles will behave. A fabric that's 95% cotton and 5% spandex will have more give than 100% cotton.
Check the fiber content and garment description. Words like 'oversized,' 'tailored,' or 'relaxed fit' are clues to how the designer intended the piece to sit.
Step six · 1 minute
Build a personal size reference
Create a simple note on your phone or in your email drafts with your measurements and a list of brands with notes about how they fit you. Example: 'Everlane: true to size, runs long. Gap: size up in tops, true to size in bottoms.' Update it as you learn. This becomes your personal shopping guide and eliminates the guesswork.
Include the date you added each brand note. Sizing can shift over time, especially if a brand changes manufacturers.
How to know it's working
You'll recognize your true size is locked in when you can predict fit before trying something on, when you stop buying multiple sizes 'just in case,' and when the clothes you order actually fit on the first try. You'll also stop blaming your body when something doesn't fit—because you'll understand it's a brand's cut, not your measurements.
Questions at the mirror.
What if I'm between sizes on the brand's chart?
Check the reviews for that specific style. If the brand runs generous, size down. If it runs small, size up. If it's true to size and you're genuinely between sizes, consider the fit priority: if you need room in the bust, size up; if you need a tighter waist, size down. You can always tailor.
Do I need to remeasure myself regularly?
Your measurements may shift slightly with seasons, workouts, or life changes. Remeasure every six months or if you notice clothes fitting differently. Most people's proportions stay relatively consistent, but it's worth checking.
What if a brand doesn't publish a size chart?
That's a red flag. Reputable brands provide detailed measurements. Rely heavily on customer reviews in this case, and consider whether you trust a brand that won't be transparent about sizing.
Should I size up or down if I'm worried about fit?
Default to your actual measurement. Sizing up 'just in case' usually results in clothes that look sloppy. A piece that's slightly snug can be tailored or worn as intended; a piece that's too big is harder to fix.