Retirement planning clarity, without the advisor markup
ThunderHarbor runs the same math a financial advisor runs. It models your tax brackets, RMD schedule, Social Security timing, and Roth conversion window together, as one plan, not as separate tools you have to piece together yourself. Change a number and the whole projection updates instantly.
Why we built this
Most Americans don't get professional retirement advice. A full plan from a certified financial planner costs $2,000 to $5,000, and ongoing advisory fees run 0.5% to 1% of your portfolio every year. For someone approaching retirement, that often adds up to $5,000 to $15,000 a year. The decisions that matter most are mathematical, not subjective. When to claim Social Security. How aggressively to convert to Roth. How to sequence withdrawals across accounts. A computer can model each of those precisely.
ThunderHarbor runs those numbers for you. It uses current IRS tax brackets, your state's tax rules, real IRMAA thresholds, and your actual account balances and income sources, not rough estimates. It's the same math a CPA runs, without the hourly rate.
Most retirement calculators treat each question as its own tool. One page for Social Security, another for RMDs, another for Roth conversions, each running on its own assumptions. Your real finances don't work that way. Move your Social Security claiming age and your RMD schedule shifts. That changes your Medicare premiums through IRMAA. A different IRMAA tier changes how much room you have to convert to Roth before it costs you. ThunderHarbor runs all of it as one model, so a change in one place shows up everywhere else it matters.
A chart by itself doesn't explain why it looks that way. ThunderHarbor does, right in the same tab where you see the number. Why your Roth conversion stops where it does. Why one withdrawal triggers IRMAA and another doesn't. Why claiming Social Security a year later changes your taxes a decade from now. You shouldn't need an actuarial background to read your own plan.
What makes it different
One connected plan, not six calculators
Change your Social Security claiming age and your RMD schedule, IRMAA tier, and Roth conversion room update with it, in the same run. Nothing here is a standalone widget you have to reconcile against the others yourself.
Privacy by design
We encrypt your financial data at rest on our servers, and it's yours. We don't sell it, share it, or train models on it. Export an encrypted backup any time, or delete your account with one click.
What-if modeling
Retire 2 years earlier. Move to Florida. Convert aggressively for 5 years. Every scenario runs the full projection instantly, so you see exactly what it costs or saves over your lifetime before you commit to it.
Modeled person by person
For couples, each spouse has their own accounts, income, Social Security claiming age, and Roth conversion strategy. The projection tracks both of you all the way through, including what happens to the survivor's taxes and RMDs after one spouse passes.
Built to catch the cliffs
Retirement income has cliffs. Cross one dollar of MAGI and an ACA subsidy can disappear or a Medicare premium can jump a full tier. Tax Cliffs flags these before you take the withdrawal, not after the tax form arrives.
Tested against bad markets
A plan built on one smooth average return can hide how it performs in a bad one. Risk Analysis runs yours against a thousand simulated markets, plus a real historical stretch like the 1966 to 1982 stagflation years, so you know how it holds up when returns don't cooperate.
Who it's for
ThunderHarbor is built for people who are serious about their retirement, whether that's still years away or already underway. If you're 10 to 20 years out and starting to plan the decisions that will matter when you stop working, or if you're already retired and managing Social Security, RMDs, Roth conversions, and Medicare costs year to year, this tool is built for you. If you have a 401k, an IRA, or a mix of account types and want to see how the pieces fit together, the projection runs the same either way.
It's not a replacement for a financial advisor in complex situations like trusts, business ownership, or unusual income structures. For the core retirement math most working Americans face, you don't need to pay someone thousands of dollars a year to run these numbers for you.
Not financial advice
ThunderHarbor provides financial planning tools and projections for informational purposes only. Nothing on this site constitutes financial, tax, investment, or legal advice. Calculations are based on inputs you provide and publicly available IRS data. Always consult a qualified financial advisor before making significant financial decisions.
Contact
Questions, feedback, or data requests: [email protected]
ThunderSecurity LLC · United States
See it with your own numbers
Free to start, no credit card required. Premium is $47/year if you want the full year-by-year strategy behind the numbers.