The answer is that there is no nice clean number. Not all dollars are created equal.
Roth A dollar in a roth is like superman...it is worth 100% of it's full value. Those are the best dollars I own.
Traditional:A dollar in a Traditional account is not as valuable, so you likely discount it...but even then you will find that different people will have to discount it a different amount. For example...
- My wife and I are teachers and will get pensions. Those pensions will likely fill up our low tax brackets, so any time we want to take money out of the traditional accounts, it is likely to come out at a very high rate. I have to heavily discount my traditional accounts.
- The millionaire educator and his wife have tiny pensions that haven't kicked in yet, but a large amount in their traditional accounts. Plus, they only live off about 20k/year. So, they are able to withdraw their traditional funds basically tax free. They don't have discount their accounts much at all...they are loving their 403B's:)
Notice that we are both in the exact same profession, we live very similar lives, and still our situations are completely different...imagine if we had very different lives.
real estateA dollar in real estate will have to be discounted by the realtor's fees due at closing. So, perhaps a 6% discount. If their home, however, is not their homestead, then they will have to pay that 6% fee, plus capital gains...so that real estate might be discounted even more.
These are just a few examples, but hopefully you get the point. There's no simple answer. You have to look at your own situation, make projections, and do your best.