What do I need to do to recaluate my arrears from child support

Its unlikely you will get your arrears recalculated unless you can prove that you paid what you owe. What males you think it should be recalculated?

You will file a motion in court to have to reviewed. You will prove that the courts figures are wrong by proving what you paid in past years.

I was incarcerated for awhile and was being charged

Child support was charging me when I was in prison.I wrote them a letter and they stopped.bt I want to get it recaluated and if anybody knows what forms to look for

Did you go to court for a modification?

Have you talked to your case worker?

No I didn't go to court to modify

Didn't know I had one

You will have to go back to court and file a motion to modify the current child support order,
Depending on your state law, most have a min amount that will still be charged, even if you are in prison.

If the support is being collected b y a state agency, then there is a caseworker assigned to the case.

I have to add that many places will not consider a retroactive modification when it is solely based on your failure to petition for an adjustment when your circumstances changed. If you had ample time to ask for a modification, and now want a retroactive modification, the window may be closed.