I'm the first to admit I have no clue about the French tax system, but a quick search finds this [1] that suggests there are both employer and employee paid taxes. Would I be right in assuming that the reported numbers are after the employer paid taxes and before the employee paid ones?

[1] https://www.cabinet-roche.com/en/payroll-taxes-in-france/

TBH for the average employee it doesn't matter if the company or you are paying, it gets deducted automatically anyway.

There are websites [0] that will help you do the conversion Brut/Net easily

[0] https://www.salaire-brut-en-net.fr/