How To · Fashion · Shopping
Find Your True Size Across Every Brand
Sizing is deliberately inconsistent—brands use vanity sizing, vintage proportions, and international standards interchangeably. The only reliable method is knowing your own measurements and learning to decode each brand's specific fit.
5 min read · IrisA size 8 at Everlane bears no relationship to a size 8 at Madewell. A vintage Levi's 32 waist is actually 31 inches. Japanese brands size down two full sizes from American standards. This isn't chaos—it's business. Understanding your actual body measurements and how to cross-reference them against brand-specific size charts is the only way to shop with confidence.
This guide walks you through taking accurate measurements, interpreting size charts like a pro, and building a personal size reference sheet so you never waste money on returns again.
Your size doesn't exist in a vacuum. It only matters relative to how each individual brand cuts and measures their garments.
What you'll need.
- 01Soft fabric tape measure
- 02Phone or notebook for recording measurements
- 03Spreadsheet or notes app
- 04Brand size charts
- 05Product reviews
Step one · 2 minutes
Measure yourself properly
Use a soft fabric tape measure, not a metal one. Wear a fitted bra or thin top—no layers. Measure bust at the fullest point, waist at your natural narrowing (not where you wear jeans), hips at the fullest point of your rear, and inseam from your inner thigh to ankle. Write these numbers down in inches or centimeters and keep them in your phone. These are your baseline measurements, independent of any brand's naming system.
Have someone else take measurements if possible—you'll get more accurate results, especially for shoulder width and back length.
Step two · 1 minute
Stop trusting the tag
The number on a garment's tag is a marketing tool, not a measurement. A brand's size 6 is whatever they decided to call their size 6—it could fit a 34-inch bust or a 36-inch bust depending on their target customer and profit margins. Vanity sizing (making clothes larger while keeping the number small) is standard practice. The tag is essentially useless for predicting fit across brands.
If a brand's size 8 fits you perfectly, that doesn't mean size 8 will fit at another brand. Start fresh each time.
Step three · 2 minutes
Locate and read the brand's size chart
Before adding anything to your cart, find the size chart. Most brands hide it near the product photos or in a dropdown menu. Compare your measurements—not the tag size you usually wear—against the chart's measurements. If you're a 34-inch bust and the size 4 measures 35 inches across the chest, that's your size, regardless of what you normally buy. Pay special attention to length measurements for tops and dresses; these vary wildly and determine whether something will hit at your hip or your knee.
Screenshot or bookmark size charts from brands you shop frequently. They sometimes change without warning.
Step four · 2 minutes
Account for fabric and fit style
A stretchy jersey knit will fit differently than a rigid cotton twill, even in the same size. A relaxed-fit shirt runs larger than a fitted shirt. A high-waisted pant sits differently than a mid-rise. Read the product description for fabric content and fit notes. If a dress is described as 'oversized' or 'fitted,' adjust your size choice accordingly. Natural fabrics like linen and cotton have less give; synthetic blends and knits offer more stretch.
Check the product photos for how the garment actually drapes on a body, not just the flat lay. This tells you whether it's meant to be close or loose.
Step five · 2 minutes
Build your personal size reference sheet
Create a simple spreadsheet or note with brand names and the sizes that fit you. Include notes on fit (runs small, true to size, generous) and any quirks (long sleeves, narrow shoulders). After three or four purchases from a brand, you'll have reliable data. Update it as you shop. This becomes your personal shopping decoder—far more useful than any generic advice about 'what size you are.'
Include links to each brand's size chart in your reference sheet so you can quickly compare measurements while shopping.
Step six · 1 minute
Use customer reviews as a secondary check
Read reviews specifically looking for fit comments. Phrases like 'runs small,' 'generous in the chest,' or 'longer than expected' are gold. Multiple reviewers saying the same thing is more reliable than the brand's own size chart, which can be aspirational. However, remember that reviewers have different body shapes than you—their feedback is a clue, not a guarantee.
Ignore reviews that just say 'perfect fit' without detail. Look for specific comparisons: 'I usually wear size 8 and sized up to 10 here.'
How to know it works
You'll know this system is working when you stop opening packages with dread and when your return rate drops to near zero. The real victory is buying clothes that fit on the first try—not because you got lucky, but because you made an informed decision based on actual data.
Questions at the mirror.
What if I'm between sizes on the chart?
Size up if you prefer a relaxed fit or the fabric has no stretch. Size down if you prefer fitted silhouettes or the fabric is stretchy. Check reviews to see which direction the brand typically leans. When in doubt, size up—taking in is easier than letting out.
Do international brands size differently?
Yes. European sizes run small relative to American sizes (a EU 36 ≈ US 4). Japanese brands typically size down two full sizes. UK and Australian brands often use their own systems. Always use the numerical measurements on the chart, not the letter or number size, to compare across countries.
Why do my measurements change?
They shouldn't significantly, but weight fluctuations, posture, and how tightly you measure do matter. Remeasure yourself once a year or if you've had major body changes. A quarter-inch difference usually won't affect fit; a full inch means you need to reassess your size.
What about vintage or secondhand brands?
Vintage sizing is notoriously inconsistent—even within the same brand and year. Always ask for specific measurements from the seller rather than relying on the tagged size. Measure garments you already own that fit well and compare those measurements to the item you're considering.