English to French Law/Patents Law (general) Divorce

Il s'agit des lignes directrices en matière de pension alimentaire dans un état américain.
Voici deux exemples dans mon texte. Ce qui me chiffonne c'est de bien rendre "guideline formula". Jai pensé à "formule directive" au lieu de "formule des lignes directrices", mais il y a sûrement de meilleures façons de l'exprimer?

Thus, even under [name of case], there is no basis here for a reduction in the ***guideline formula*** amount of child support for Xxx's travel expenses for visitation.

He contends, however, that this case falls within the one exception to the changed circumstances rule, identified in [an another case],
for modification of child support orders that do not conform to the ***guideline formula***. In his view, "[t]he support order did not meet the guideline [once Jennifer turned 18] because there was no appropriate manner to calculate timeshare."