Calculator plugin required for Wordpress site

Hi all I have a client who needs a calculator plugin installed to his WordPress site. I am currently developing an existing site that someone was working on before but they failed to deliver this calculator. The existing calcultor is on an old site and it works perfectly. I tried to copy it over but it had some custom coding before. I have not got access to the old cPanel as I would of copied that over. This needs to be done in the next few hours. I will provide the excel sheet for calculations. I need you to provide either a free plugin or tell me one that will work. I am quite happy to buy it ($15) I need you to copy all the data over to the new calculator and make it work like the old site URLs will be given to potential freelancers. Thanks Paul