How Fit Finder Works and What Advice It's Based On
Fit Finder by Prime AI solves this problem using advanced predictive AI technology to guide shoppers to the right size accurately and instantly. At its core, Prime AI Fit Finder uses predictive modelling and machine learning to recommend the best size for each individual shopper. This isn’t based on generic size charts. It’s a recommendation personalised to your customer, your products, and your brand.
Depending on your setup, shoppers can:
- Enter a few basic details such as: height, weight, body shape, fit preference.
- Enter brand names and sizes that they own and fits them well.
- Or, for returning customers, get instant recommendations with Zero Input based on their previous purchases, returns.
Behind the scenes, the system uses:
- SKU-level product data (fit, fabric, style, stretch)
- Real customer reviews (extracted with LLMs to identify mentions of tightness, length, etc.)
- Purchase and return history across your store
- Brand-to-brand sizing correlations
- Fit clusters based on real-world behavior of similar shoppers
- All of this combines to produce highly accurate sizing advice in milliseconds.
But how exactly does it work? And what makes our advice different from the rest?
How Different Prime AI Fit Finder Is?
Unlike tools that rely on rigid size charts or crowd-sourced guesses, Prime AI builds a unique neural network for each retailer and even for each shopper. Prime Size Finder system constantly learns and adapts:
- Shopper-Level AI: Size suggestions adapt over time based on the customer’s actions and preferences
- SKU-Level Learning: Product-level size behavior is tracked and refined over time
- Cross-Product Intelligence: If a product is returned frequently in one size, the system flags it and adapts future recommendations
- We also learn from negative outcomes, returns and non-conversions, so every failed purchase sharpens the model.
Getting Started with Fit Finder
Prime AI offers two powerful solutions tailored to your business needs:
Lite Version – Free on Shopify
- Installs in minutes with no coding required
- Helps shoppers choose the right size based on simple inputs
- Ideal for smaller retailers or those looking to start fast
- Supports multiple languages and is mobile-optimised
- Install Size Finder Lite for free. Install Now!
Pro Version – 100% Customisable with Zero-Input Option
- Delivers size recommendations without any user input (no quizzes or forms)
- Learns from real data: past purchases, returns, reviews, shopper behavior, and SKU-level product details, brand to brand comparison and all these moving parts are cross learning
- Achieves over 99% accuracy, validated by live customer results
- Built for enterprise retailers using Shopify Plus, Salesforce Commerce Cloud, Magento, or custom stacks
- Offers deep insights: refund analytics, size demand trends, missed sale detection, and more. Explore the Pro version now!
Prime AI’s Fit Finder isn’t one-size-fits-all, it’s built to evolve with your business
Whether you’re launching quickly with our free Lite version or investing in predictive, zero-input sizing technology with the Pro version, you’ll empower your shoppers, reduce returns, and boost profitability.
Both solutions are built for scale, privacy-first, and backed by years of real-world data.
Ready to see how Fit Finder can work for your store? Book Demo Now!
See how Clothing Size Finder Pro has helped brands slash returns
Designed for Speed, Built for Fashion
Prime AI was created to fit the rhythm of real life. Our technology works in the background, so shoppers don’t have to stop, measure, or doubt. Instead, they flow naturally through the buying journey, from browsing to basket in minutes.
Unlike older rule-based sizing solutions, our system adapts to changes in product shape, brand fit, or customer preference. It can even distinguish between styles that require a looser or tighter fit, like tailoring versus loungewear, and recommend accordingly.
Whether you’re a fast fashion powerhouse or a premium heritage brand, the result is the same: fewer returns, higher trust, and a smoother mobile journey.
Fashion Is Fast. Fit Should Be Too.
In today’s mobile world, attention spans are shorter than ever. If your shopper can’t make a confident choice in under 30 seconds, they’ll scroll away.
Size uncertainty is one of the last major friction points in online fashion, and it’s especially painful on mobile. Prime AI eliminates this uncertainty with intelligence, speed, and style.
The fashion industry has already digitised its storefronts, its payments, and its supply chains. Now, it’s time to modernise the most human part of shopping: fit.
Take the First Step Toward Smarter Sizing
Whether you’re aiming to improve your first-time buyer conversions, reduce return rates, or simply offer a more personalised experience, we’re ready to help.
Let’s make sure your shoppers find their fit, the first time, every time.
