Is there a standard way to determine the bit width of hardware?

Question

Variables of type int are supposedly "one word of a machine type in length" but in embedded systems, C compilers for 8-bit microconsumption have int 16 bits !, (8 bits for unsigned char), then for more bits int behaves normally: in 16- bit int microns are also 16 bits, and 32 bit int microns - 32 bits, etc.

So, is there a standard way to test it, something like BITSIZEOF (int)?

like "sizeof" for bytes, but for bits.

That was my first idea.

    register c=1;                
    int bitwidth=0;
    do
    {

        bitwidth++;

    }while(c<<=1);

    printf("Register bit width is : %d",bitwidth);

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#include <limits.h>

const int bitwidth = sizeof(int) * CHAR_BIT;

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