Measurement price calculator

[CJW]

Hi, I am wanting to sell something that requires the customer entering a custom width and height of a product and then a price automatically shown for the sizes inputted. I have spread sheets with all the widths on the "x" and heights on the "y" and the product values shown for the sizes ( hope that makes sense ). Would this be able to have a code written? I have seen a few apps that offer this but are a high monthly cost and have received some bad reviews that put me off.  Many Thanks.  

[CJW]

Thanks for the reply, this is exactly what I’m wanting, could I please have more info?