Getting accurate Tkinter widget geometry: fix 1x1+0+0 on Windows with update() instead of update_idletasks()

Tkinter may report 1x1+0+0 for widgets after packing on Windows. See why winfo_geometry needs update and when to use update() instead of update_idletasks().

Getting reliable widget dimensions in Tkinter can be surprisingly tricky when you need them right after laying out the UI. On Windows with Python 3.11, calling winfo_geometry(), winfo_width(), winfo_height(), winfo_x(), and winfo_y() immediately after packing widgets may report 1x1+0+0 or zeros for child widgets, even though the root window looks correct. The discrepancy disappears after a user interaction or a full update of the GUI event loop.

Minimal example that reproduces the issue

The following code builds a simple layout and prints the geometry of the root and several frames. The logic is standard: create styles, place widgets, then query their geometry after calling update_idletasks(). The labels also show geometry when buttons are pressed.

import tkinter as tk
from tkinter import ttk

class DemoApp:
    def __init__(self, master):
        self.master = master
        self.master.title("Window title")
        self.master.geometry("800x600")
        self.init_styles()
        self.layout_widgets()
        self.dump_metrics()

    def init_styles(self):
        self.sty_dark = ttk.Style()
        self.sty_dark.configure('ThemeDark.TFrame', background='#343434')
        self.sty_lg = ttk.Style()
        self.sty_lg.configure('AccentGreen.TFrame', background='#a4edde')
        self.sty_lb = ttk.Style()
        self.sty_lb.configure('AccentBlue.TFrame', background='#73d9eb')

    def layout_widgets(self):
        self.pane_canvas = ttk.Frame(self.master, style='ThemeDark.TFrame', width=500)
        self.side_panel = ttk.Frame(self.master, style='AccentGreen.TFrame', width=200)

        self.btn_one = ttk.Button(self.pane_canvas, text='btn_1', command=self.on_btn_one)
        self.lab_one = ttk.Label(self.pane_canvas, text="lbl_1", width=40)
        self.btn_one.pack()
        self.lab_one.pack()

        self.pane_canvas.pack_propagate(0)
        self.pane_canvas.pack(side='left', fill='both', expand=True)
        self.side_panel.pack_propagate(0)
        self.side_panel.pack(side='left', fill='both', expand=False)

        self.hdr_one = ttk.Frame(self.side_panel, style='AccentBlue.TFrame')
        self.btn_two = ttk.Button(self.hdr_one, text='btn_2', command=self.on_btn_two)
        self.lab_two = ttk.Label(self.hdr_one, text="lbl_2", width=40)
        self.btn_two.pack()
        self.lab_two.pack()
        self.hdr_one.pack(side='top', fill='x', expand=False)

        self.hdr_two = ttk.Frame(self.side_panel, style='ThemeDark.TFrame')
        self.btn_three = ttk.Button(self.hdr_two, text='btn_3', command=self.on_btn_three)
        self.lab_three = ttk.Label(self.hdr_two, text="lbl_3", width=40)
        self.btn_three.pack()
        self.lab_three.pack()
        self.hdr_two.pack(side='top', fill='x', expand=False)

    def on_btn_one(self):
        self.lab_one.config(text=self.pane_canvas.winfo_geometry())
        self.dump_metrics()

    def on_btn_two(self):
        self.lab_two.config(text=self.hdr_one.winfo_geometry())
        self.dump_metrics()

    def on_btn_three(self):
        self.lab_three.config(text=self.hdr_two.winfo_geometry())
        self.dump_metrics()

    def dump_metrics(self):
        self.master.update_idletasks()
        self.pane_canvas.update_idletasks()
        self.side_panel.update_idletasks()
        self.hdr_one.update_idletasks()
        self.hdr_two.update_idletasks()

        print('self.master.winfo_geometry()', self.master.winfo_geometry())
        print('self.master.winfo_height()', self.master.winfo_height())
        print('self.master.winfo_width()', self.master.winfo_width())
        print('self.master.winfo_x()', self.master.winfo_x())
        print('self.master.winfo_y()', self.master.winfo_y())

        print('self.pane_canvas.winfo_geometry()', self.pane_canvas.winfo_geometry())
        print('self.pane_canvas.winfo_height()', self.pane_canvas.winfo_height())
        print('self.pane_canvas.winfo_width()', self.pane_canvas.winfo_width())
        print('self.pane_canvas.winfo_x()', self.pane_canvas.winfo_x())
        print('self.pane_canvas.winfo_y()', self.pane_canvas.winfo_y())

        print('self.side_panel.winfo_geometry()', self.side_panel.winfo_geometry())
        print('self.side_panel.winfo_height()', self.side_panel.winfo_height())
        print('self.side_panel.winfo_width()', self.side_panel.winfo_width())
        print('self.side_panel.winfo_x()', self.side_panel.winfo_x())
        print('self.side_panel.winfo_y()', self.side_panel.winfo_y())

        print('self.hdr_one.winfo_geometry()', self.hdr_one.winfo_geometry())
        print('self.hdr_one.winfo_height()', self.hdr_one.winfo_height())
        print('self.hdr_one.winfo_width()', self.hdr_one.winfo_width())
        print('self.hdr_one.winfo_x()', self.hdr_one.winfo_x())
        print('self.hdr_one.winfo_y()', self.hdr_one.winfo_y())

        print('self.hdr_two.winfo_geometry()', self.hdr_two.winfo_geometry())
        print('self.hdr_two.winfo_height()', self.hdr_two.winfo_height())
        print('self.hdr_two.winfo_width()', self.hdr_two.winfo_width())
        print('self.hdr_two.winfo_x()', self.hdr_two.winfo_x())
        print('self.hdr_two.winfo_y()', self.hdr_two.winfo_y())

if __name__ == '__main__':
    win = tk.Tk()
    app = DemoApp(win)
    win.mainloop()

What’s actually going on

Tk determines widget sizes and positions lazily. Immediately after creating and packing widgets, geometry negotiation has not necessarily finished, and early calls to winfo_… can return placeholders such as 1x1+0+0. The reference describes this behavior explicitly.

w.winfo_geometry() Returns the geometry string describing the size and on-screen location of w.

Warning The geometry is not accurate until the application has updated its idle tasks. In particular, all geometries are initially '1x1+0+0' until the widgets and geometry manager have negotiated their sizes and positions. See the .update_idletasks() method, above, in this section to see how to insure that the widget's geometry is up to date.

Before using the winfo_ methods, you need to let Tk finish creating and laying out the widgets at the internal GUI level. You can do this with update_idletasks() or with update(). Alternatively, you can query winfo_reqwidth() and winfo_reqheight(), which report the size a widget wants to be rather than its final geometry.

On Ubuntu using X11, the example above reports correct values after update_idletasks(). On Windows 10 and Windows 11, the same code can still print 1x1+0+0 for child widgets until update() is used. Switching to update() resolves the problem on Windows.

Fix: force a full GUI update before reading geometry

Replacing update_idletasks() with update() ensures Tk processes what it needs so that geometry becomes accurate across the described environments.

import tkinter as tk
from tkinter import ttk

class DemoApp:
    def __init__(self, master):
        self.master = master
        self.master.title("Window title")
        self.master.geometry("800x600")
        self.init_styles()
        self.layout_widgets()
        self.dump_metrics()

    def init_styles(self):
        self.sty_dark = ttk.Style()
        self.sty_dark.configure('ThemeDark.TFrame', background='#343434')
        self.sty_lg = ttk.Style()
        self.sty_lg.configure('AccentGreen.TFrame', background='#a4edde')
        self.sty_lb = ttk.Style()
        self.sty_lb.configure('AccentBlue.TFrame', background='#73d9eb')

    def layout_widgets(self):
        self.pane_canvas = ttk.Frame(self.master, style='ThemeDark.TFrame', width=500)
        self.side_panel = ttk.Frame(self.master, style='AccentGreen.TFrame', width=200)

        self.btn_one = ttk.Button(self.pane_canvas, text='btn_1', command=self.on_btn_one)
        self.lab_one = ttk.Label(self.pane_canvas, text="lbl_1", width=40)
        self.btn_one.pack()
        self.lab_one.pack()

        self.pane_canvas.pack_propagate(0)
        self.pane_canvas.pack(side='left', fill='both', expand=True)
        self.side_panel.pack_propagate(0)
        self.side_panel.pack(side='left', fill='both', expand=False)

        self.hdr_one = ttk.Frame(self.side_panel, style='AccentBlue.TFrame')
        self.btn_two = ttk.Button(self.hdr_one, text='btn_2', command=self.on_btn_two)
        self.lab_two = ttk.Label(self.hdr_one, text="lbl_2", width=40)
        self.btn_two.pack()
        self.lab_two.pack()
        self.hdr_one.pack(side='top', fill='x', expand=False)

        self.hdr_two = ttk.Frame(self.side_panel, style='ThemeDark.TFrame')
        self.btn_three = ttk.Button(self.hdr_two, text='btn_3', command=self.on_btn_three)
        self.lab_three = ttk.Label(self.hdr_two, text="lbl_3", width=40)
        self.btn_three.pack()
        self.lab_three.pack()
        self.hdr_two.pack(side='top', fill='x', expand=False)

    def on_btn_one(self):
        self.lab_one.config(text=self.pane_canvas.winfo_geometry())
        self.dump_metrics()

    def on_btn_two(self):
        self.lab_two.config(text=self.hdr_one.winfo_geometry())
        self.dump_metrics()

    def on_btn_three(self):
        self.lab_three.config(text=self.hdr_two.winfo_geometry())
        self.dump_metrics()

    def dump_metrics(self):
        self.master.update()
        self.pane_canvas.update()
        self.side_panel.update()
        self.hdr_one.update()
        self.hdr_two.update()

        print('self.master.winfo_geometry()', self.master.winfo_geometry())
        print('self.master.winfo_height()', self.master.winfo_height())
        print('self.master.winfo_width()', self.master.winfo_width())
        print('self.master.winfo_x()', self.master.winfo_x())
        print('self.master.winfo_y()', self.master.winfo_y())

        print('self.pane_canvas.winfo_geometry()', self.pane_canvas.winfo_geometry())
        print('self.pane_canvas.winfo_height()', self.pane_canvas.winfo_height())
        print('self.pane_canvas.winfo_width()', self.pane_canvas.winfo_width())
        print('self.pane_canvas.winfo_x()', self.pane_canvas.winfo_x())
        print('self.pane_canvas.winfo_y()', self.pane_canvas.winfo_y())

        print('self.side_panel.winfo_geometry()', self.side_panel.winfo_geometry())
        print('self.side_panel.winfo_height()', self.side_panel.winfo_height())
        print('self.side_panel.winfo_width()', self.side_panel.winfo_width())
        print('self.side_panel.winfo_x()', self.side_panel.winfo_x())
        print('self.side_panel.winfo_y()', self.side_panel.winfo_y())

        print('self.hdr_one.winfo_geometry()', self.hdr_one.winfo_geometry())
        print('self.hdr_one.winfo_height()', self.hdr_one.winfo_height())
        print('self.hdr_one.winfo_width()', self.hdr_one.winfo_width())
        print('self.hdr_one.winfo_x()', self.hdr_one.winfo_x())
        print('self.hdr_one.winfo_y()', self.hdr_one.winfo_y())

        print('self.hdr_two.winfo_geometry()', self.hdr_two.winfo_geometry())
        print('self.hdr_two.winfo_height()', self.hdr_two.winfo_height())
        print('self.hdr_two.winfo_width()', self.hdr_two.winfo_width())
        print('self.hdr_two.winfo_x()', self.hdr_two.winfo_x())
        print('self.hdr_two.winfo_y()', self.hdr_two.winfo_y())

if __name__ == '__main__':
    win = tk.Tk()
    app = DemoApp(win)
    win.mainloop()

Why this detail matters

Reading accurate geometry is a building block for dynamic layouts, custom drawing, and placing overlays. If your code makes layout decisions or logs metrics immediately after packing, platform-specific differences can lead to confusing results. Ensuring the GUI has progressed far enough before querying avoids inconsistent state and makes behavior predictable across environments.

Takeaways

Query geometry only after Tk has finalized layout. Use update_idletasks() or update() before calling winfo_… methods; if you need the target size rather than the final size, rely on winfo_reqwidth() and winfo_reqheight(). On Windows, replacing update_idletasks() with update() resolves the case where widgets still report 1x1+0+0 after layout. Keeping this in mind will help you build cross-platform Tkinter UIs that report consistent geometry from the moment they appear.