[quote]The state is Ohio.
The order was given in March.
They based the income off of overtime not base pay.
there are three children, Ages 16,13,11. [/quote]

All income counts when it comes to calculating child support, not just base pay.

What is usually done with overtime is that an average over a 3 year period is used.

You aren't going to be able to exclude overtime from the child support calculations, especially if it occurs regularly.