I am looking at adding products for a client that include made-to-measure curtains. 

So we need to be able to have the user enter a measurement in millimeters in a text box (along with other variations and attributes), and using a formula it will calculate and display the price.

Is this possible? 

And if not possible out-of-the-box with Zoho Commerce, is it possible using Creator’s Formula Language (FACE)?
//assuming Commerce supports FACE as a custom integration?//