Size Chart
A standardised reference guide listing garment measurements for each size your brand offers — critical for reducing returns, building customer trust, and ensuring consistent fit across global markets.
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What is Size Chart?
A size chart is a standardised reference table that lists the body or garment measurements for each size a brand offers. With 67% of all fashion e-commerce returns caused by sizing issues, the size chart is arguably the single most important product page element — it directly affects purchase confidence, conversion rates, and return costs.
Types of size charts:
- Body measurement chart: Lists the customer's body measurements for each size (e.g., "Size M: bust 36", waist 30""). Helps shoppers match themselves to a size.
- Garment measurement chart: Lists the actual finished garment dimensions (e.g., "Size M: chest 40", length 28""). Shows the real product dimensions including ease allowance.
- Combination chart: Shows both body and garment measurements side by side — this is the gold standard that top-performing brands use.
Understanding ease — the hidden cause of returns:
The difference between body measurements and garment measurements is called "ease." There are three types:
- Wearing ease: Minimum extra space needed to move, sit, and breathe (present in all garments, typically 2–4" at chest)
- Design ease: Additional room added intentionally for the silhouette — an oversized hoodie has high design ease, a bodycon dress has nearly zero
- Negative ease: The garment is actually smaller than the body measurement — used for stretch fabrics like swimwear, activewear, and compression garments
Most customers do not understand ease. When a customer with a 36" bust orders a "Size M" and receives a garment measuring 40" at the chest, they may think it is too big — even though those 4" of ease are intentional. Explaining this on your size chart page dramatically reduces confusion-based returns.
Key measurements by garment type:
Tops & shirts:
- Chest/bust width
- Shoulder width
- Sleeve length
- Garment length (front and back)
- Hem width
Bottoms (pants, trousers, skirts):
- Waist
- Hip
- Inseam/outseam
- Thigh circumference
- Hem opening (leg opening)
- Rise (front and back)
Dresses & jumpsuits:
- All top measurements + skirt/total garment length + waist position from shoulder
Size naming conventions across markets:
- Alpha sizing: XS, S, M, L, XL, XXL — the most universally recognised system, used globally
- Numeric (US): 0, 2, 4, 6, 8, 10, 12, 14 — standard in American womenswear
- Numeric (UK): 6, 8, 10, 12, 14, 16 — approximately 4 numbers higher than US equivalents (UK 14 ≈ US 10)
- European: 34, 36, 38, 40, 42, 44 — note that French, German, and Italian "EU sizes" can differ by 2–4 points despite all being called "European"
- Asian: Sizes typically run 2–3 sizes smaller than US/EU. Korean sizing uses cm-based codes (55, 66, 77). Japanese sizing (S/M/L) is cut for a slimmer frame than Western equivalents.
- Numeric (waist-based): 28, 30, 32, 34, 36, 38, 40 — common in menswear, denim, and ethnic/formal wear across South Asian markets
Why sizes vary between brands:
There is no mandatory global sizing standard. The US voluntary standard (ASTM D5585) was last significantly updated decades ago, and brands are free to define their own measurements for any size label. This is why a "Medium" from one brand can fit completely differently from another — and why vanity sizing exists (a US women's size 12 in 1958 corresponds to approximately a size 6 today).
Why This Matters for Fashion Entrepreneurs
Size-related returns account for 30–40% of all fashion e-commerce returns globally, and 63% of online shoppers admit to "bracketing" — buying multiple sizes with the intention of returning what doesn't fit. Each return costs brands $21–46 in shipping, restocking, and lost resale value. A well-built size chart and fit recommendation system can reduce returns by 25–40%.
Building your size chart:
- Start with anthropometric data for your target market: Use ASTM D5585 (US), BS EN 13402 (Europe), JIS L4005 (Japan), or NIFT studies (India) as your measurement baseline
- Choose your fit philosophy: Relaxed, regular, or slim — document it and stay consistent across all styles
- Test on diverse body types: Fit garments on at least 3–5 people per size, not just one fit model. Body proportions vary significantly across demographics — bust-to-waist ratios, torso length, and hip proportions differ across South Asian, East Asian, European, and American populations
- Grading consistency: Maintain consistent 1.5–2" (4–5 cm) increments between sizes across all styles. If your Medium chest is 40" and Large is 42", that 2" grade must be consistent from shirts to jackets to dresses
- Include both measurement systems: Always show both inches and centimeters — your customers are global
Common sizing mistakes that kill conversion:
- Using a single sizing standard for all global markets without conversion guidance
- Inconsistent sizing between styles (a Medium in one product fits differently than Medium in another)
- Not accounting for fabric stretch — stretch fabrics need different grading than wovens
- Showing only body measurements OR only garment measurements instead of both
- No plus-size or extended sizing (the global plus-size market is growing at 5.9% CAGR)
- Placing the size chart in the footer instead of on the product page itself
- Using an image-based size chart that isn't readable on mobile devices
Sourcing Guide
Size chart development resources:
- ASTM D5585 (US): The voluntary American standard for body measurements — your baseline for US-targeted sizing
- BS EN 13402 (Europe): European standard using body dimensions in centimeters
- JIS L4005 (Japan): Japanese Industrial Standard for garment sizing
- NIFT anthropometric studies (India): Indian body measurement data
- Competitor benchmarking: Measure actual garments from 5–10 competitor brands in your category — this reveals real-world grading practices
- Professional pattern makers: Experienced pattern makers in your target market know local body proportions and fit preferences
Fit technology tools:
- True Fit: AI-powered size recommendation used by Nike, Gap, and Target — 80 million active users, reduces bracketing returns by up to 24%
- Bold Metrics: Creates a digital twin with 50+ body measurements for style-by-style recommendations
- 3DLOOK: Two-photo body scanning for accurate sizing
- Kiwi Sizing: Shopify-native size chart and recommendation app
- Sizely / Size.ly: Online size recommendation tools ($35–180/month / ₹3,000–15,000/month)
Size guide presentation best practices:
- Place the size chart directly on every product page (not buried in a help section)
- Use responsive HTML tables, not images — images break on mobile and are invisible to search engines
- Provide a clear "how to measure yourself" section with illustrations
- Show the model's height, weight, and size worn ("Model is 5'7" / 170 cm, wearing size M")
- Add a size recommendation quiz or tool if budget allows
- Always display both inches and centimeters
Pricing & Costs
Size chart development costs:
- DIY (competitor benchmarking + testing): $0 / ₹0 (your time investment)
- Professional pattern maker or size consultant: $60–250 / ₹5,000–20,000 for complete size chart development
- Body scanning / anthropometric study: $600–2,500 / ₹50,000–2,00,000 (for larger brands needing custom data)
- AI size recommendation tool (website integration): $35–180/month / ₹3,000–15,000/month (Kiwi Sizing, True Fit, Sizely)
The ROI case:
- Average fashion return rate: 30–40% of all orders
- Average cost per return: $21–46 (shipping + restocking + lost resale value)
- 63% of shoppers bracket (buy multiple sizes to return the rest)
- Reducing size-related returns by just 10% on 1,000 orders/month at $25/return saved = $2,500/month saved
- A $250 size chart investment pays for itself within the first week
- Brands using AI-powered fit tools like True Fit have seen 10% return reduction, 27% increase in average order value, and measurable conversion rate improvements
Frequently Asked Questions
Body measurements are the actual dimensions of a person's body (bust, waist, hips), while garment measurements are the dimensions of the finished clothing item. Garment measurements are always larger than body measurements because of "ease" — the extra room built into every garment for movement and comfort. For example, if your bust measures 36 inches, a regular-fit Size M top might measure 40 inches at the chest, giving you 4 inches of wearing ease. This difference is the number one cause of sizing confusion and returns, which is why the best size charts show both types of measurements side by side.
Start by choosing a base size (typically Size M or Size 8 for womenswear, Size M or 40 for menswear). Fit your sample garment on a fit model or dress form that matches your target customer's proportions. Record all key measurements: chest, waist, hip, shoulder, sleeve length, garment length, and inseam where applicable. Then apply consistent grading increments (typically 1.5–2 inches / 4–5 cm between sizes) to create your full size range. Test the graded sizes on real people across at least 3 body types per size. Finally, create both a body measurement chart (for customers to match their size) and a garment measurement chart (showing actual product dimensions). Professional size chart development typically costs $60–250.
Most new brands start with 5–7 sizes: XS through XL or XXL (or numeric equivalents like US 2–14). This covers approximately 80% of the market while keeping production costs and inventory manageable. As your brand grows, consider extending in both directions — adding XXS for petite customers and 2XL–4XL for plus-size inclusivity. The plus-size fashion market is growing at 5.9% CAGR with significant unmet demand. Key rule: never launch with fewer than 4 sizes, and always ensure your grading increments are consistent so customers can trust that sizing is predictable across your entire collection.
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