Angular 2 material mat-tab size

If you want to control the height and width of angular material tabs use styles followed by ::ng-deep. Check the below code to modify height and width

::ng-deep .mat-tab-label
{
  height: 27px !important;
  min-height: 5px!important;
  margin: 3px!important;
  width: 90px!important;
  min-width: 5px!important;
}

Without !important:

/* 
    ::ng-deep disables view-encapsulation of Angular components 
        -> to avoid global style bleeding use it in combination with :host
        -> https://angular.io/guide/component-styles#deprecated-deep--and-ng-deep
*/
:host ::ng-deep .mat-tab-label {
    min-width: 100px;
}

Try this:

/deep/.mat-tab-label, /deep/.mat-tab-label-active{
 min-width: 0!important;
 padding: 3px!important;
 margin: 3px!important;
}

NOTE: In angular 8 /deep/ not working... you can use ::ng-deep, like so:

::ng-deep.mat-tab-label, ::ng-deep.mat-tab-label-active{
 min-width: 0!important;
 padding: 3px!important;
 margin: 3px!important;
}

In my case the accepted answer didn't work well - when switching between tabs the width of body of specific tab was changing and it didn't look nice, so I added mat-tab-link to resolve it

::ng-deep.mat-tab-link,  ::ng-deep.mat-tab-label, ::ng-deep.mat-tab-label-active{
    min-width: 97px!important;
}