Ember action on='change' event

I have this ember action helper (which is just for experimenting)

{{input type='number' action='calculateMph' on='change'}} mph = {{controller.mph}} km/h

If I remove the on='change' it works fine when I press enter. But with on='change' it simply doesn't work at all. And the debugger isn't giving me anyting.

Am I doing something wrong? I want the action to run as you type into the input field and update the value live.

Here's my controller if it's any help.

var HomeController = Ember.Controller.extend({
  mph: null,

  actions: {
    calculateMph: function(parameter) {
      var result = parameter * 1.60934
      this.set('mph', result);
    }
  }
});

Note that I'm using ember CLI