At a glance
Killion is planning and simulation software with read-only account linking. FI Calc is described below in its own terms. Where a figure is quoted it comes from the vendor's published pricing and was checked on the date shown.
| Killion | FI Calc | |
|---|---|---|
| Individual price | $14/mo, or $11/mo billed annually ($132/yr). Max tier $24/mo or $19/mo annually. | Free. No account required. |
| Free entry point | Live no-signup Monte Carlo demo on a fictional household, plus a 5-day free trial of the full product. Card required for the trial; no charge until it ends. | The entire product is free. |
| Account linking | Read-only brokerage and crypto linking via SnapTrade. Cash and bank balances are entered manually while automatic bank linking moves to a new provider. | None. You type the portfolio, allocation and spending. |
| Simulation method | 1,000-path regime-switching Monte Carlo with fixed seeds, so a run reproduces. | Historical simulations in the Bengen tradition: rolling start years on real market data, with a published success rate. |
| Historical backtesting | Historical backtesting against real market data going back to 1928. | Yes — that is the product. |
| Withdrawal rules | Nine named rules: fixed real dollar, fixed percentage, Guyton-Klinger, Vanguard dynamic, endowment smoothing, VPW, CAPE-based, risk-based guardrails, and Merton. | Many named strategies (including VPW), each with a short explainer of the identity and a configurable equation. |
| AI assistant | Built-in AI assistant with access to your connected holdings and plan. | None. |
| Human advice | None. Killion is software; it is not a registered investment adviser. | None. It is a calculator. |
FI Calc details checked on against the FI Calc guide. Vendors change prices; verify before deciding.
What FI Calc actually is
FI Calc (ficalc.app) is a retirement calculator that replays a plan through historical market sequences, in the tradition of Bengen and the Trinity study. The public guide states that you can recreate those original results, change the horizon and the withdrawal, and explore alternative withdrawal strategies. Results can be exported as CSV. There is no account wall.
That is a different job from Killion. FI Calc answers “how often would this withdrawal rule have survived history.” Killion answers “what happens to this household, with these linked holdings, across 1,000 seeded regime-switching lifetimes, and across history.” Both questions are worth asking. They are not the same question.
Account linking is the other half
Review-site roundups that rank “retirement planning software with account linking” do not list vendor landing pages, and a dedicated landing page will not rank there. The argument still belongs on a comparison. FI Calc does not link accounts; you type the numbers. Killion links brokerages read-only through SnapTrade so the plan’s starting balance is the one the brokerage reports, not the one you remembered.
Which one to choose
Choose Killion if
- You want the plan to update when brokerage holdings change, not when you re-type them.
- You want a seeded Monte Carlo that models clustered bad years, not only historical start years.
- You want budgeting, net worth and the projection in one product.
Choose FI Calc if
- You want to pay nothing and create no account.
- You specifically want rolling historical start-year success rates, the way Bengen did it.
- You want to export every path to CSV and finish the work in a spreadsheet.