Found a couple of budget spread sheets etc. on the web.
Then went through all of my spending for the last 3 months.
Plugged everything in, trying to over estimate vs under.
Ended up with a monthly expense of ~$3k vs my original bad guess of ~$1k/month.
Very big error. Thank FIRE folks for the inquisitive questions.
The biggest monthly expenses were: Insurance and Gas. Both of these will drop a bit when I retire.
I also have one more kid to help with college. I have a prepaid college program paid off that gets him 120 semester hours. I have to pay for books and lodging.
We put 2 other kids through college already and the cost was about $600 to $1000/month.
So, for the last one, if I retire this will be an expense of about $48k for 4 years. This will come out of our cash reserves.
Any feedback?