1. You Have A Large Number Of Assets
As mentioned, if you expect to have a large number of assets in a Traditional IRA or 401(k), eventually you're going to need to pay taxes on that when you make withdrawals.
In addition, there will be required minimum distributions.
2. You Expect Higher Future Taxes
Not a lot of us will have so much money in our retirement funds that a Roth conversion would help. However, there will be times when our income puts us in a lower tax bracket.
You can plan your conversions to coincide with these times. Converting to a Roth IRA in timed increments is a helpful way to avoid higher taxes on large conversions.
A Roth conversion calculator can help you figure out how much to transfer and when. What you'll be doing is spreading out the income and therefore spreading out the taxes you'll pay.
Tax brackets come in ranges. So, for example, if you make 100,000 and the next tax bracket up is $150,000, you can convert as much as $50,000 and still be in the same tax bracket.
3. Your 401k Is With Your Previous Employer
Another thing to consider is an old 401(k) from an employer you no longer work for. Do you really want an old employer to manage your retirement fund? Or do you want that control yourself?
4. You Want To Avoid RMDs
Roth IRAs don't have required minimum distributions, you can continue to accumulate money in your Roth IRA and withdraw from other retirement accounts.
#5: Better Access To Your Savings
Finally, you can use the money in a Roth IRA to help with the downpayment on a new home without penalty. If you are a first-time homebuyer, this is a great advantage.