Question

I have a rather complex formula that I want to recreate with code, I have set up a fiddle
But I have no idea where to start with the JavaScript/jQuery?

Any help to get me started and point me in the right direction would be wonderful.

The formula I need is

(1/(1 - A %)) - 1 = B %
A = Percentage drop (#input)
B = Percentage gain (#output)

For example: If A drops with 25%, B has to increase 33% to break even

I would like the output to be displayed on click of the Calculate div, then in the future I would like to use a jQuery slider to change the input value and have the output change dynamically.

<div id="calc">
<div id="inputlabel">INPUT</div>
<input id="input">%</>
<div id="calculation">CALCULATE</div>
<h1 class="output">%</h1>
</div>​

Answer 1

This code will work:

$(document).ready(function() {
    $('#calculation').click(function() {
        var inp = parseFloat($('#input').val());
        var out = parseFloat((1 / (1 - (inp / 100))) - 1);
        out = parseInt(out * 100);
        $('h1.output').text(out + ' %');
    });
});

Check the updated fiddle.