You can convert as little or as much each year that you want to. It is often a good tax strategy to only convert as much each year that does not push you into a higher tax bracket because of the taxable amount of the conversion.
(I don't know if you are close to age 70 1/2, but keep in mind that at 70 1/2 you must start taking RMD's (Required Minimum Distribution) from Traditional IRA's and no part of a RMD can be rolled over of converted to a Roth so you would want to complete the Roth conversions prior to that age.)
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
