Size Calculator That Helps Cut Sizing Returns
By Mohit Patel, Marketing Specialist, Tailor Size Guide
Returns cut deep into fashion margins: the National Retail Federation estimates 19.3% of online sales were returned in 2025, and size and fit are among the most common reasons clothing comes back. 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?
It depends on your products and how accurate your size data is, so measure it in your own store: compare size-related return rates for the 60 to 90 days before and after you add the calculator. The biggest gains usually come on products whose size charts were missing or inaccurate.
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?
There is a free plan, so you can try it on your store before paying. Check the Shopify App Store listing for current plans and trial terms.
Related calculators
Run a fashion store on Shopify?
Add this calculator to your product pages. Per-product size charts, instant fit recommendations, and fewer sizing-driven returns.