Every floating window may have its own size.
For example, if countdown text is to small for you, you can simply enlarge the countdown floating window using countdown menu:

How to change a floating window size using floating window menu:
Zoom - use it to resize a floating window size
1. Zoom In - use it to enlarge a floating window size
2. Zoom Out - use it to decrease a floating window size
3. Actual Size - restores the actual a floating window size
4. Full Screen - use it to set a floating window size to the screen size (press Esc to get back to the previous size of a floating window). This feature is very useful for live-events (conferences, presentations etc.) - you can show on a big screen how long is left till coffee break/luncheon or you can use stopwatch/timer in timing speakers to keep your conference/presentation within the time allowed.

How to change a floating window size using mouse:
Just point mouse cursor to the right-bottom corner of the floating window, you want to resize, and change the size by dragging the corner:

If you point the mouse cursor to the right or bottom border of a floating window - you can change the size without zooming (it means, you can enlarge floating window size but keep text size without changes):