Roth Conversion Worksheet in Excel / Exact tax math / Fix Logic / Create Graph / Create Heatmap

I already have a semi working workbook that models annual balances, tax liability, and cumulative after-tax wealth for my Roth conversion plan, but several pieces still need attention. It needs to fill down and absolutely calculate tax numbers correctly. See description.

The comparison chart that should overlay “cumulative after-tax wealth at plan end” against “total taxes paid over time” is no longer updating correctly. See Screenshots
Next, I’d like to automate a sensitivity analysis. A VBA macro should:
• Iterate the annual Roth conversion amount in $2,500 steps, 50 columns across (up to $125 k).
• Populate a new table where each row is an additional plan year through the full horizon.
• Recalculate cumulative after-tax wealth and taxes for every cell.
• Apply conditional formatting to show a red-yellow-green heat map, making it obvious when an extra $2,500 conversion helps and by how much.
• Clear prior results and rerun everything when I click a single “Run Analysis” button.

All necessary inputs—balances, returns, tax brackets, time horizon—are already on dedicated sheets, so please reference those ranges rather than hard-coding. I’m open to design suggestions that improve readability, as long as the color logic remains intuitive for non-technical users.

Deliverables

• Fixed, dynamic chart comparing cumulative wealth vs. taxes.
• Fully commented VBA macro that builds the analysis table and heat map, and an additional separate table showing the most efficient Roth Conversion amount if applicable, in one click.
• Clean, user-friendly layout ready for further what-if work.
I’m on Excel 365; Let’s lock the calculations first, then polish the visuals.