Why does winfo_width() return a larger size of button widget than the size of what it exactly looks like?

I want buttons/labels in the same column will share the same width with a specific/first button/label. The problem is winfo_width() seems not to return what I want. The return value of winfo_width() is multiple times the button.

I don't want to make width fixed by a number I select. Thus, I did not find a solution to my problem.

Here is part of my code:

button_1.update_idletasks()
print(button_1.winfo_width())
new_label = Label(frame_1, bg=  "#8432C7", width = 30, height = 5)
new_label.grid(row = 2, column = 0)

Since I don't have 10 reputation to post images, here is the link for the generated interface:

If you could see the above image, you should find the lower label (width = 30) is larger than the upper button (width = 157 ?).

But, according to my attempts, 157 seems not to be the width of button_1. I feel confused about what exactly winfo_width() returns here. Thus, I want to know what winfo_width() returns (why winfo_width() return 157 which should be a smaller number than 30) and how to get the exact width of the button.

I am stuck here for an hour since I just started to learn Tkinter recently. Thanks in advance for anyone who can give me suggestions.