Convert Excel Spreadsheet Calculator to Web App

I need to take an existing excel spreadsheet calculator that uses Macros and convert it into a simple, clean, yet fully functional web application so that it can be used on mobile devices. The calculator's purpose is for field engineers to input data values against the algorithms to validate their tests. No knowledge of the specific algorithms or engineering is required. Algorithms are fully functional and contained in the existing spreadsheet. I only wish to have this spreadsheet converted into a web app accessible from any and all tablet/phones. Knowledge of macros will be required. The spreadsheet contains roughly 25 input fields and a summary worksheet that displays the final calculations. A screenshot image (.png) of the current spreadsheet layout is included in the attachments. I look forward to working with you.