The entry in wikipedia,

This [the LM statistics] follows a chi-squared distribution, with degrees of freedom equal to the number of estimated parameters (in the auxiliary regression) minus one.

A rapid inspection of the original article of White (1980) confirm this (eq. 2, eq. 3, and Corollary 1 in the article should be what you are looking for).

The entry in wikipedia,

This [the LM statistics] follows a chi-squared distribution, with degrees of freedom equal to the number of estimated parameters (in the auxiliary regression) minus one.

A rapid inspection of the original article of White (1980) confirms this (eq. 2, eq. 3, and Corollary 1 in the article should be what you are looking for).

The entry in wikipedia,

This [the LM statistics] follows a chi-squared distribution, with degrees of freedom equal to the number of estimated parameters (in the auxiliary regression) minus one.

A rapid inspection of the original article of White (1970) confirm this (eq. 2, eq. 3, and Corollary 1 in the article should be what you are looking for).

The entry in wikipedia,

This [the LM statistics] follows a chi-squared distribution, with degrees of freedom equal to the number of estimated parameters (in the auxiliary regression) minus one.

A rapid inspection of the original article of White (1980) confirm this (eq. 2, eq. 3, and Corollary 1 in the article should be what you are looking for).