I need a small basic Tax Refund Calculator Building into a WordPress Themed Website

General information for the website: I am building a website for an accountant and he wants a UK Refund Tax Calculator building into the site. We have the data etc and the site is built
Kind of development: Customization of existing website
Description of requirements/features: I am currently building a website for a accountant. We have built the website in WordPress.

We need to someone to help build a UK Tax Refund Calculator. The site is built we just need this adding.

We have the Tax Refund Calculator information and sum it does to do. This has been supplied by the customer.

We have the data in a excel document.

We need the Calculator building and then putting on the site so it works front end.

The Calculator is not complex at all.

All this calc needs to do is the following:

Field for:

- Total Income
- Tax Paid

The calc then needs to go to column A and find the income. Then minus Column B figure from the amount inputted for Tax paid. The difference is the Refund amount due which is what we want the calc to show.
Specific technologies required: Must be easy to put in a wordpress based website
Extra notes: We need this building asap. Only quote is you can build quickly and also install on the webiste