balance-windows

balance-windows is an interactive compiled Lisp function in `window.el'.

It is bound to C-x +.

(balance-windows &optional WINDOW-OR-FRAME)

Balance the sizes of windows of WINDOW-OR-FRAME.
WINDOW-OR-FRAME is optional and defaults to the selected frame.
If WINDOW-OR-FRAME denotes a frame, balance the sizes of all
windows of that frame. If WINDOW-OR-FRAME denotes a window,
recursively balance the sizes of all child windows of that
window.