I’ll be selling curtains on my Shopify website. My customer must select the width and length when purchasing the product. The width can be adjusted in centimeters up to 10 meters, calculated as the total fabric used: width * 2.5. The length can be adjusted up to 3 meters. This can vary from product to product. For some products, I need to adjust this manually, and the length does not affect the price. The width should be multiplied by 2.5 according to the product price. how can i do it ?
I saw one site somewhat similar to what you are looking for.
Check out the carpet products. Here the length is fixed though.
Hi @nukleermen
Looks like you’re setting up a custom curtain store on Shopify — exciting!
If you want customers to enter width and length, and have the price auto-calculate based on width × 2.5 × product price, Easify Product Options can handle it easily. You can set numeric inputs, apply custom pricing formulas, and even set different min/max values per product — all without coding. Here’s how it works:
- This is the result:
- This is the app setting:
You can set the unit, as well as the minimum and maximum values, for each dimension.
Then, you can set your price formula so it updates automatically when customers enter any dimension.
This app is very straightforward and works perfectly for customizable products. Reach out to Easify if you need any assistance! 
Hello @nukleermen
You can achieve this with either line item properties or a product options app, depending on how flexible you want it to be.
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Line item properties let you add fields where your customer can enter the desired width and length. However, these won’t automatically adjust the price – you’d need some custom code or an app for that.
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If you need the price to be calculated automatically (e.g. width × 2.5 × product price), then a product options app is usually the easiest way. That way, you can set rules per product, allow for manual adjustments, and make sure only the width affects the price while length is just for info.
Some merchants build this with Shopify’s custom product options and a bit of custom Liquid/JS to handle the calculation. But unless you’re comfortable coding, I’d recommend using an app – it’s much faster and keeps things maintainable.
For example, with our own app we’ve built specifically for custom measurements (width/length/area), you can set up formulas like price = width × 2.5 × base price, while letting the length be just an informational field. It also supports different limits per product (e.g. max 10m width, max 3m length).
If you’d like, I can point you to the app and show you how it works for a curtains setup.
Kind regards,
Floris de Vries