A tax tool built by someone who files returns.

The Roth Conversion Calculator is made by Nalepa Labs LLC — the software company founded by Piotr (Peter) Nalepa, EA, a practicing Enrolled Agent with twenty years inside small and mid-size accounting practices.

It exists because the Roth conversion decision is one of the highest-leverage planning moves a preparer makes, and most tools either oversimplify it to a marginal rate or ask you to upload the client's whole return to a server. This one does neither: it models the bracket, IRMAA, and NIIT interaction, and it does all of it in your browser, on your machine.

It lives on its own domain because it answers to a single promise — do the job well, and keep the client's data where it belongs. More single-purpose tax utilities, built to the same standard, may follow.