You can override the canvas style width !important …
canvas{
width:1000px !important;
height:600px !important;
}
also
specify responsive:true,
property under options..
options: {
responsive: true,
maintainAspectRatio: false,
scales: {
yAxes: [{
ticks: {
beginAtZero:true
}
}]
}
}
update under options added : maintainAspectRatio: false,
link : http://codepen.io/theConstructor/pen/KMpqvo