I have gotten conflicting information on whether you need earned income to convert a regular IRA to a Roth. Do you need earned income?

You absolutely DO NOT need earned income to do a IRA to Roth conversion. Anyone that told you this does not know what they are talking about and you absolutely do not want to use them for tax advice. You might be prohibited on doing a conversion either because your income is too high, or because of your tax filing status, or the combination of those factors. Converting in a year with low or zero income is beneficial because you may be paying tax on the conversion amount.... and this could lower your rate. In a a few instances, you may be able to convert a small amount with no tax obligation.

Conversion math is not terrible complicated, but I highly recommend that if you have not read cover to cover IRS Pub 590 and understand what you have read, then you should consult with a tax preparer or tax accountant familiar with conversions. If the dollar amount is significant, spend the money for advice in advance of a conversion so that you get it right.

Can a converson from traditional IRA to Roth be completed by surviving spouse, age 80, who is taking RMD from deceased husband's IRA (transferred ownership after husband died)?