microcontroller - What value to use to convert ADC value to voltage?

While working on my project, I got to a point where I don't know the answer. I have a 10-bit ADC (the one incorporated in the ATMEGA328P) and it returns values up to 1023 (2¹⁰ - 1).

The official documentation states that the equation to convert the values from the ADC to the corresponding voltage is:

$$V = \frac{V_{in} \cdot ADC}{2^{10}}$$

But, if the values go up to 1023, then wouldn't it be better to replace the 2¹⁰ by 2¹⁰ - 1?

Thanks.