Green River Staff

Green River Converts Spreadsheet Calculators into Javascript for Browser-based Use

Green River continues to expand our expertise in the conversion of special-purpose Excel-based calculators into online, browser-based calculators. This service conveys a number of benefits to clients and the public.

Barriers to Widespread Use Many special-purpose calculators have been written using MS-Excel. You can find them all over the Internet, for everything from planning low-calorie meals to divining carbon footprints. A limitation is that they only run in spreadsheet applications like Excel, so you have to download them from websites in order to use them. This method of delivery tends to put off many users, who don’t take the time to download the files and run them in the required spreadsheet application. Green River recognizes the importance of special-purpose calculators developed using spreadsheets, but needed to convert them to a browser-based presentation affordably.

.XLS to .JS Conversion Our solution brings together a number of our skills, including graphic design, user experience design, Javascript programming, and our capacity to work with the models coded in spreadsheets. What we do is translate the contents of spreadsheet files into Javascript code that will run in all the main browsers (Firefox, Safari, Chrome, etc.). A spreadsheet file contains the formulas, data, and formatting information that govern how a spreadsheet works. You may have noticed that you can view an .XLS file using a text editor. You will see a compact, cryptic mass of data, formulas, and notation. The MS-Excel application uses this to build the properly formatted spreadsheet you experience when you use Excel, and updates the .XLS file as changes are saved.

With the expertise we have accumulated from a growing series of assignments of this kind, Green River converts the spreadsheet file into a web-ready Javascript program. Then we create a web page within our client’s website that calls and runs this Javascript code so that the user can conveniently use the calculator. Our service thus consists of two parts: converting an .XLS file that contains a calculator into a .JS file (which is done once), and assisting in the implementation of the Javascript calculator through our client’s website. In addition to widely disseminating the client’s models in an intuitive and usable manner, this solution also provides the added benefits of enabling our client to collect data about how the online calculator is used by website visitors, and enabling them to integrate the calculator with social media, such as Facebook, Twitter, and LinkedIn.

Example: VBSR’s health care reform finance calculator Vermont Businesses for Social Responsibility ( has developed a number of calculators for their members (we’re a member!). A recent calculator allows users to model alternative ways of financing Vermont’s planned universal health insurance system, coming in 2017. Users are invited to assemble their own financing plan for the state’s anticipated system, and then submit the results to VBSR’s policy staff for its advocacy work. With convenient sliders and a pie chart of the results, the tool includes revenue options such as payroll taxes, income taxes, sales taxes, rooms and meals taxes, and assessments placed on carbon emissions and sugar-based drinks. The results allow VBSR to speak authoritatively about how its members want to finance universal health care. Green River assisted VBSR with the Javascript conversion and web-page implementation of this calculator, shown below.

See the live calculator.

And here’s a May 19th press release describing the calculator.

VBSR Health Care Finance Calculator

Examples: Calculators for Vermont Health Connect Green River converted and deployed a number of calculators for Vermont Health Connect, Vermont’s new online health exchange under the Affordable Care Act.

We implemented a “Small Employer Estimator” that’s intended to help Vermont’s businesses determine if their business is eligible to use Vermont Health Connect, and compare the costs of continuing to offer health insurance with not offering health insurance. We also created a “Subsidy Calculator” that helps users to estimate their tax credits before they enroll in a health plan. A third example for Vermont Health Connect is an “Affordability Calculator,” which helps employees figure out whether their health coverage is considered adequate and affordable.

See the screen shots below, or visit a live calculator.

VHC Small Employer Estimator Calculator

VHC Subsidy Calculator

VHC Affordability Calculator