"M or L?"
Faced with two sizes, some shoppers close the tab. Others order both and send one back.
Solutions

How size recommendation software calculates each shopper's size in your own size chart, no photo needed, and how to choose the right tool.
It is a tool placed on the product page, next to the size selector, that gives each shopper their size for that specific product. They answer a few questions they already know; the tool does the calculation in the product's size chart.
Your size chart is accurate, but your shoppers do not know their body measurements. They want an answer, not a table.
Faced with two sizes, some shoppers close the tab. Others order both and send one back.
A parcel coming back, an item to restock, a refund, and often a lost order.
What returns really cost: read our guide to fashion e-commerce return rates and our article on e-commerce returns.

Gender, height, weight and age. Nothing to measure.
Upper body, stomach, hips: the shopper picks the image that looks most like them.
The WeeFizz engine derives 14 girth and length measurements.
These measurements are compared with the product's size chart, taking the garment's ease into account.
Key point: size recommendation works with no photo needed. Virtual try-on uses a photo, but the size is still calculated by the recommendation. The difference is explained in virtual try-on or size recommendation?

Three approaches exist. They do not ask the shopper for the same thing and do not give them the same answer.
| Size chart | Fit quiz | Size recommendation | |
|---|---|---|---|
| What the shopper does | Measures themselves with a tape measure, then reads the chart | Answers questions about the sizes they usually wear | Answers a few questions they already know |
| What they get | Centimetres to interpret alone | An indication, based on the quiz rules | A size, calculated in the product's size chart |
| Between two sizes | "M or L?" stays unanswered | Depends on the questions asked | Body shape and the garment's ease decide |
| Per product | One chart per product or per collection | Often one shared rule | The size chart of each product |
| What you learn | Nothing | Varies by tool | Usage, recommended sizes, conversion, per product |
The size chart remains the starting point. The engine is explained in detail in our expertise on body shape and ease.
They apply to WeeFizz as much as to any other size recommendation tool. Ask them before you install.
A table, however well designed, leaves the calculation to the shopper.
Your size chart, product by product, not a generic one.
A tape measure, a photo or a few answers: every extra step makes some shoppers give up.
Without usage and conversion analytics, you cannot know whether the tool pays off.
Hosting, GDPR, consent for e-mail addresses: demand precise answers.
A trial on your own catalogue, with your own figures, is worth more than a generic demo.
The same "Find my size" widget and the same WeeFizz dashboard, whatever your platform. Looking for a size advisor on Shopify, PrestaShop or WooCommerce? Choose your installation guide.
Custom site? The JavaScript SDK adds the same widget. Plans and the free trial are on the pricing page; the demo is on the WeeFizz Fashion page.
It is a tool placed on the product page that gives each shopper their size for that specific product. Instead of reading a table of centimetres on their own, they answer a few questions and get a size, calculated in the product's size chart, before adding to basket.
No. With WeeFizz, they enter their gender, height, weight and age, then choose their body shape from images. No photo, no tape measure. Virtual try-on, which uses a photo, is a separate service: the size itself is still calculated without a photo.
The shopper's answers become 14 girth and length measurements. These measurements are compared with the product's size chart, set up as it is and calibrated by WeeFizz, taking the garment's ease into account. Jeans, a hoodie and a dress each keep their own chart.
A size chart gives centimetres that shoppers must compare with their own body measurements, which they rarely know. Size recommendation does that calculation for them, from the same size chart, and gives them one answer: a size.
WeeFizz Fashion is available as a Shopify app (WeeFizz Size Recommender), a PrestaShop module, a WooCommerce plugin and a JavaScript SDK for custom sites. The widget and the WeeFizz dashboard are the same everywhere.
No. A recommendation is the best possible estimate based on the size chart provided. It reduces hesitation, but no serious tool promises zero errors. The right approach: measure the effect on your own store, with your own figures.
Every WeeFizz Fashion plan starts with a 14-day free trial, with no commitment. You install the widget on your catalogue and follow, in your dashboard, widget usage, recommended sizes and conversion, product by product.
Equipping employees rather than online shoppers? Read our guide to remote workwear sizing.
Try size recommendation on your catalogue for 14 days, with no commitment.
