getPPI : function(){
	var DOM_body = document.getElementsByTagName('body')[0];	
	var DOM_div = document.createElement('div');
	DOM_div.style = 'width: 1in; visibility:hidden;';
	DOM_body.appendChild(DOM_div);
	var w = document.defaultView.getComputedStyle(DOM_div, null).getPropertyValue('width');
	DOM_body.removeChild(DOM_div);
	return parseInt(w);
}

Outputs the number of Pixels Per Inch in the current Device

Get PPI of the current device displaying your page

javascript

JavaScript