How do you plan for early retirement when you can't predict family expenses?

[MWM1220]

Hi all!

My husband and I are very new to mustachianism. and marriage for that matter. RIght now, we're newlyweds. We both have awesome jobs with flexible hours that make it possible for us to do additional part time stuff and awesome salaries. However - it won't always be this way. We predict at last 2 children in our future, if not some extras on top of that number. So is the best practice just to be living as frugally as possible and build my stache as much as possible... or is there a way to calculate the right percentage?

Don't know if this was worded super eloquently. Just pondering. Would love to have a "goal" that we're shooting for, but maybe it's too early in the race to put a fine point on it? How do you folks who have reached early retirement calculate for life changes like these or others?

[arebelspy]

So is the best practice just to be living as frugally as possible and build my stache as much as possible...

Yes.

I'm in the same boat of having no idea what my FIRE expenses will be.  We're planning on having kids and traveling full time.  What will those things cost?  Who knows. 

Save as much as you can as early as you can and as it gets closer you may be able to pin down some costs.  In other cases you may need to have a buffer and/or be flexible.

[Caoineag]

Just keep tracking what you spend each year and buy the time you get there, you should have a ballpark figure. At least, that is what I am going for, lol. I figure that while what I spend on will not be the same, the amount I spend will be similar.

[MWM1220]

Awesome! thanks everyone! Still learning to control spending, just wasn't sure if there were any particulars. Thanks for your help. Here's to one day being ready for retirement.

[AllieVaulter]

I don't have kids yet either, so I can't say what my costs are.  And while, I haven't gotten through all MMM's posts yet, he and Mrs. MM have done some posts on the cost of raising kids. 

http://www.mrmoneymustache.com/2011/09/09/mrs-money-mustache-what-do-newborn-babies-really-need/

http://www.mrmoneymustache.com/2011/05/26/what-is-the-real-cost-of-raising-children/

To non-Mustachians, kids are this crazy spending expense.  But if you remember to use logic, it seems that kids don't have to be crazy expensive.  Especially if you believe this article:  http://www.colorado.edu/news/features/kids-whose-time-less-structured-are-better-able-meet-their-own-goals

[frugal_c]

You might find that there are actually 2 FIRE budgets.  One which is for you and the kids, the other after the kids are grown up.   If you can get to a point where you can cover your expenses without the kids, you could always switch down to working part-time until they are grown up and then FIRE.   That also allows you some financial flexibility, if your kids add substantially to your budget it is easier to work more with a part-time gig than it is to re-enter the work-force if you completely FIREd.