Overstay fine how I know

You must review the General Administration of Residence, in order to know the value of the fine for violating the period of residence.
It is also calculated at the rate of 100 dirhams for each day of residence in violation.
You can reduce the fine if you are leaving the UAE, and you can request a 50% reduction in exchange for a ban from entering the UAE for a year. If you want to modify your residency status by converting the visa from a visit visa to work visa, in that case you must pay the full fine, and it will not be reduced. Also, the public administration of residence is the entity to which you can apply for a reduction of the residence fine if there is justification for that.