css width: calc(100% -100px); alternative using jquery

I'd like to use width: calc(100% -100px); which does the job perfectly for what I need it for, the only problem is its compatibility. At the moment it only works in the latest browsers and not at all in Safari.

Could I make an alternative using jQuery? ie. get the 100% width of an object -100px and then dynamically set the result as the CSS width (so it would be responsive)

If you have a browser that doesn't support the calc expression, it's not hard to mimic with jQuery:

$('#yourEl').css('width', '100%').css('width', '-=100px');

It's much easier to let jQuery handle the relative calculation than doing it yourself.

I think this may be another way

    var width=  $('#elm').width();
                    
    $('#element').css({ 'width': 'calc(100% - ' + width+ 'px)' });

100%-100px is the same

div.thediv {
  width: auto;
  margin-right:100px;
}

With jQuery:

$(window).resize(function(){
  $('.thediv').each(function(){
    $(this).css('width', $(this).parent().width()-100);
  })
});

Similar way is to use jQuery resize plugin

Try jQuery animate() method, ex.

$("#divid").animate({'width':perc+'%'});

Its not that hard to replicate in javascript :-) , though it will only work for width and height the best but you can expand it as per your expectations :-)

function calcShim(element,property,expression){
    var calculated = 0;
    var freed_expression = expression.replace(/ /gi,'').replace("(","").replace(")","");
    // Remove all the ( ) and spaces 
    // Now find the parts 
    var parts = freed_expression.split(/[\*+-\/]/gi);

    var units = {
        'px':function(quantity){
            var part = 0;
            part = parseFloat(quantity,10);
            return part;
        },
        '%':function(quantity){
            var part = 0,
            parentQuantity = parseFloat(element.parent().css(property));
            part = parentQuantity * ((parseFloat(quantity,10))/100);
            return part;
        } // you can always add more units here.
    }
    
    for( var i = 0; i < parts.length; i++ ){
        for( var unit in units ){
            if( parts[i].indexOf(unit) != -1 ){
               // replace the expression by calculated part.
               expression = expression.replace(parts[i],units[unit](parts[i]));
               break;
            }
        }
    }
    // And now compute it. though eval is evil but in some cases its a good friend.
    // Though i wish there was math. calc
    element.css(property,eval(expression));
}

If you want to use calc in your CSS file use a polyfill like PolyCalc. Should be light enough to work on mobile browsers (e.g. below iOS 6 and below Android 4.4 phones).