For chart.js V2 (beta), use:
var options = {
scales: {
yAxes: [{
display: true,
ticks: {
suggestedMin: 0, // minimum will be 0, unless there is a lower value.
// OR //
beginAtZero: true // minimum value will be 0.
}
}]
}
};
See chart.js documentation on linear axes configuration for more details.