tk.Menu items are very small in CustomTkinter

[limafresh]

I have a Full HD screen. Everything is fine with a regular tk.Tk window:

import tkinter as tk
# import customtkinter as ctk
from tkinter import messagebox

root = tk.Tk()
root.geometry("400x300")

menubar = tk.Menu(root)

file_menu = tk.Menu(menubar, tearoff=0)
file_menu.add_command(label="Open")
file_menu.add_command(label="Save")
menubar.add_cascade(label="File", menu=file_menu)

root.config(menu=menubar)

root.mainloop()

But with the ctk.CTk window the menu items are small:

import tkinter as tk
import customtkinter as ctk
from tkinter import messagebox

root = ctk.CTk()
root.geometry("400x300")

menubar = tk.Menu(root)

file_menu = tk.Menu(menubar, tearoff=0)
file_menu.add_command(label="Open")
file_menu.add_command(label="Save")
menubar.add_cascade(label="File", menu=file_menu)

root.config(menu=menubar)

root.mainloop()

Can anyone help? I know about CTkMenuBar by Akascape, but I want to try the native menu.

[kalyanamdewri]

This is most likely DPI scaling, not the menu code itself.

CTk() enables CustomTkinter's automatic high-DPI handling on Windows. CustomTkinter then scales CTk widgets/window geometry itself, but tk.Menu is a native Tk/Tkinter menu, not a CTk widget, so it can end up looking smaller than the rest of the app.

Quick test:

import customtkinter as ctk

ctk.deactivate_automatic_dpi_awareness()  # call before CTk()
root = ctk.CTk()

If the menu size matches tk.Tk() after that, the cause is confirmed. The tradeoff is that on Windows with display scaling above 100%, disabling automatic DPI awareness can make the whole window look blurry.

So the practical options are:

1. Keep automatic DPI awareness and use a CTk-based menubar/dropdown implementation.
2. Disable automatic DPI awareness before creating the root window if native tk.Menu size is more important than sharp DPI rendering.
3. Avoid mixing native Tk menus with scaled CTk widgets for UI that must look consistent across DPI settings.

set_widget_scaling() will not fully solve this because it applies to CustomTkinter widgets, not the native tk.Menu menu.

Docs: https://customtkinter.tomschimansky.com/documentation/scaling/

[limafresh]

So, it's better not to use tk.Menu in CustomTkinter? On Full HD, scaling makes everything bigger compared to when scaling is disabled, but for some reason, menu items are the opposite – they are smaller.

[kalyanamdewri]

Not necessarily "do not use it", but I would treat tk.Menu as a compromise in a CustomTkinter app.

tk.Menu is still the native Tk menu. It is not drawn by CustomTkinter, so it does not follow CustomTkinter's widget scaling or theme styling the same way CTk widgets do. If a native OS-style menu is acceptable, it is fine to keep using it. If you want the menu to visually match the rest of the CTk UI across display/DPI settings, a CTk-based menu/menubar will usually behave more consistently.

The opposite-looking scaling is expected on Windows. When automatic DPI awareness is disabled, Windows can bitmap-scale the whole app, so the native menu may look bigger. When CustomTkinter enables DPI awareness, Windows stops stretching the window; then CustomTkinter scales its own widgets manually, but the native tk.Menu keeps using Tk/OS menu metrics. So relative to the scaled CTk widgets, the menu can look smaller.

If you want to keep tk.Menu, you can also try setting the menu font yourself before/when creating the menu, for example:

root.option_add("*Menu.font", ("Segoe UI", 10))

or:

menubar.configure(font=("Segoe UI", 10))
file_menu.configure(font=("Segoe UI", 10))

That may be enough if only the text size bothers you, but it still will not make tk.Menu a fully scaled/themed CustomTkinter widget.