height property

double? height
final

The height of the Tab.

If null, the height will be calculated based on the content of the Tab. When icon is not null along with child or text, the default height is 72.0 pixels. Without an icon, the height is 46.0 pixels.

The provided tab height cannot be lower than the default height. Use PreferredSize widget to adjust the overall TabBar height and match the provided tab height:
link
bottom: const PreferredSize(
  preferredSize: Size.fromHeight(20.0),
  child: TabBar(
    tabs: <Widget>[
      Tab(
        text: 'Tab 1',
        height: 20.0,
      ),
      Tab(
        text: 'Tab 2',
        height: 20.0,
      ),
    ],
  ),
),

Implementation

final double? height;