Size Calculator That Cuts Returns 30%+
Returns kill margin in fashion — the average apparel return rate is 30%, and 70% of those returns are sizing-driven. This reduce-returns size calculator is the Shopify app version of what shoppers use here: per-product measurements, instant fit recommendations, and stored shopper data that follows them across every product in your store. Use the calculator below to get your exact fit in 30 seconds.
How it works
Measure yourself
Take your bust, waist, and hips with a soft tape. See the full measurement guide.
Enter the numbers
Type your measurements into the calculator above. Pick inches or cm — the tool converts both ways.
Get your size
Match the result against the brand's chart and order with confidence.
Women's tops & dresses — bust-driven sizing
| Size | US | UK | EU | Bust |
|---|---|---|---|---|
| XS | 0–2 | 4–6 | 32–34 | 31–33" |
| S | 4–6 | 8–10 | 36–38 | 33–35" |
| M | 8–10 | 12–14 | 40–42 | 35–37" |
| L | 12–14 | 16–18 | 44–46 | 38–40" |
| XL | 16–18 | 20–22 | 48–50 | 41–43" |
| XXL | 20–22 | 24–26 | 52–54 | 44–46" |
Frequently Asked Questions
How much can a size calculator actually reduce returns?
Brands using Tailor Size Guide report 25–40% reduction in sizing-driven returns within 90 days. The math: 30% return rate × 70% sizing-driven × 30% calculator catch = ~6 percentage points off your return rate.
How does it integrate with Shopify?
Free Shopify app install. Embeds on product pages via Theme Editor. Per-product size charts, brand-wide measurement saving, and analytics dashboard.
What about non-fashion categories?
Tailor Size Guide is built for apparel, footwear, and accessories. For homewares or electronics, you don't need this.
Is there a free trial?
Yes — 14-day free trial on every plan. Install from the Shopify App Store.
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Run a fashion store on Shopify?
Add this calculator to your product pages. Per-product size charts, instant fit recommendations, and 30%+ reduction in sizing-driven returns.