Menu
Request a Demo
Menu

Size Finder Lite - Now Available on Shopify App Store - Free

AI Learns from Sales and Refunds

Prime AI’s Size Finder continuously improves by learning from your real-world data. Every sale and every size-related return helps train the system to better understand how your products fit on different body types.

When customers return items due to sizing issues such as “too small” or “too large,” that information is fed back into the AI. Over time, our model adapts to your specific product catalogue, fit variations across collections, and even seasonal trends in shopper behaviour.

This dynamic feedback loop allows Prime AI to deliver increasingly precise size recommendations, tailored to how your customers actually experience fit.

Sales and refund data is one of several key data streams used by our system. Combined with other signals, such as body profile inputs, conversion outcomes, and product metadata – it powers a smarter, more context-aware sizing experience.

Back to comparison ➔

Why it matters

Fit accuracy improves over time, which means fewer returns, higher conversion rates, and more satisfied shoppers.

Because the AI is constantly learning from your own customers, it becomes better aligned with your brand’s fit profile, your product range, and your shopper segments – delivering long-term value that generic size tools can’t match.

Request a Demo

Still not sure which is right for you?

Reviews

Anna - Digital Director (UK)
Handy tool and fantastic customer service
The tool allows us to offer accurate fitting information to our customers, including information based on returns to maintain accuracy. The Prime AI team are very helpful if/when issues arise, and are quick at responding and solving problems, as well as suggesting new ways the tool can be implemented.
Denis - Performance Marketing Manager (Romania)
Efficient Cooperation
Our cooperation with Prime AI is very successful, we are happy with the results. Also, optimisation of the tool has been implemented after multiple feedback sessions to which Prime AI has been very open. The UX was not the best, but after multiple feedback sessions, things got fixed.
Rosie - Head of e-commerce and brand (UK)
Great software and amazing account management
Prime AI's account management and monthly reports/ recommendations have been brilliant. We have been able to customise the platform to suit our needs and no ask is ever too much 🙂 ... We have been able to make informed, strategic business decisions and the product is great from a user interface point of view with seamless integration.

Case Studies

multi-brand fashion return reduction case study showing how Prime AI’s size recommendation tool helped reduce return rates and improve sizing confidence in online fashion retail.
Multi-brand Fashion Return Reduction – How Prime AI Reduced Returns Across 14 Brands

Multi-brand Fashion Return Reduction – How Prime AI Reduced Returns Across 14 Brands

speedo return reduction case study showing how Prime AI’s size recommendation tool helped reduce return rates and improve sizing confidence in online fashion retail.
Speedo Return Reduction: How Prime AI Slashes Returns

Speedo Return Reduction: How Prime AI Slashes Returns

new balance return reduction case study showing how Prime AI’s size recommendation tool helped reduce return rates and improve sizing confidence in online fashion retail.
New Balance Return Reduction: How Prime AI Slashes Returns

New Balance Return Reduction: How Prime AI Slashes Returns

puma return reduction case study showing how Prime AI’s size recommendation tool helped reduce return rates and improve sizing confidence in online fashion retail.
Puma Return Reduction: How Prime AI Slashes Returns

Puma Return Reduction: How Prime AI Slashes Returns

under armour return reduction case study showing how Prime AI’s size recommendation tool helped reduce return rates and improve sizing confidence in online fashion retail.
Under Armour Return Reduction: How Prime AI Slashes Returns

Under Armour Return Reduction: How Prime AI Slashes Returns

the north face return reduction case study showing how Prime AI’s size recommendation tool helped reduce return rates and improve sizing confidence in online fashion retail.
The North Face Return Reduction: How Prime AI Slashes Returns

The North Face Return Reduction: How Prime AI Slashes Returns

Nike return reduction case study showing how Prime AI’s size recommendation tool helped reduce return rates and improve sizing confidence in online fashion retail.
Nike Return Reduction: How Prime AI Slashes Returns

Nike Return Reduction: How Prime AI Slashes Returns

reebok return reduction case study showing how Prime AI’s size recommendation tool helped reduce return rates and improve sizing confidence in online fashion retail.
Reebok Return Reduction: How Prime AI Slashes Returns

Reebok Return Reduction: How Prime AI Slashes Returns

Ellesse return reduction case study showing how Prime AI’s size recommendation tool helped reduce return rates and improve sizing confidence in online fashion retail.
Ellesse Return Reduction: How Prime AI Slashes Returns

Ellesse Return Reduction: How Prime AI Slashes Returns

Champion return reduction case study showing how Prime AI’s size recommendation tool helped reduce return rates and improve sizing confidence in online fashion retail.
Champion Return Reduction: How Prime AI Slashes Returns​

Champion Return Reduction: How Prime AI Slashes Returns​

Adidas return reduction case study showing how Prime AI’s size recommendation tool helped reduce return rates and improve sizing confidence in online fashion retail.
Adidas Return Reduction: How Prime AI Slashes Returns

Adidas Return Reduction: How Prime AI Slashes Returns

Multi-brand retail return reduction case study showing how Prime AI’s size recommendation tool helped reduce return rates and improve sizing confidence in online fashion retail.
Multi-brand Retail Return Reduction: How Prime AI Slashes Returns

Multi-brand Retail Return Reduction: How Prime AI Slashes Returns

We analyed 1,000,000 returns. Here's what we found...

Lessons from 1,000,000 Returns" – A bold, high-contrast digital artwork featuring a stylish woman in an off-shoulder dress, overlaid with abstract textures in blue, pink, and black. The vibrant design highlights the key theme of inconsistent sizing in fashion, a major driver of returns in online retail.
Inconsistent Sizing in Fashion: Shocking Insights from Analysing 1 Million Returns

Inconsistent Sizing in Fashion: Shocking Insights from Analysing 1 Million Returns

Bracketing in online shopping – Lessons from 1,000,000 returns. Image of a woman wearing a navy knit two-piece outfit, with a futuristic digital background.
Bracketing in Online Shopping – Lesson 2 from 1M Returns

Bracketing in Online Shopping – Lesson 2 from 1M Returns

A stylish model in a blue-striped outfit with a digital data background, representing insights from analysing 1 million online returns. Text overlay reads ‘Lessons from 1,000,000 Returns – 3’, reinforcing the key theme of how poor fit leads to lost customers.
Poor Fit Leads to Lost Customers – Lesson 3: Stop Return-Driven Churn

Poor Fit Leads to Lost Customers – Lesson 3: Stop Return-Driven Churn

Request a Demo
Menu
Menu

This site uses cookies

By continuing to use our site, you consent to the Privacy Policy terms. If you agree to our terms, ‘Accept Privacy Policy’. See our Privacy policy for more information.

Accept Privacy Policy