Launching today
FinSim
See how kids, debt & retirement shape your wealth
18 followers
See how kids, debt & retirement shape your wealth
18 followers
Unlike most financial simulators, FinSim shows you two side-by-side scenarios so you can see exactly how carrying debt, having children, and your retirement timeline interact over decades. Debt— model your payoff timeline and see how it frees up wealth long-term. Child costs—powered by real NDCP childcare data specific to your county. Financial independence age—based on the 4% rule, updated in real time as you adjust your inputs. Built by a solo developer in SwiftUI. Free, no ads, no purchases.
@matthew_feliciano Upvoted. This tackles a decision that most people think about emotionally but rarely break down financially, so I can see the value in making the tradeoffs easier to understand. Congratulations on the launch. How did you decide which financial assumptions to include without making the simulator too complicated?
@spotch_founder Great question and honestly one of the harder design decisions. The short answer is I drew a line between assumptions that change the shape of the projection meaningfully versus ones that just add precision without changing what you'd actually decide. Things like inflation, salary growth curves, and regional childcare costs clear that bar since they move the lines on the chart in ways that matter. Things like Roth conversion ladders or capital gains harvesting are genuinely important but they interact with individual tax situations in ways that would require a full tax engine to model honestly, and I didn't want to fake precision I couldn't actually deliver. The goal was a model that's directionally honest rather than superficially detailed. That said, a proper tax layer is on the roadmap as the tool matures. Thanks for your feedback!
Love the side-by-side comparison and using real NDCP data for childcare costs. One thing that would make this even more useful for me is the ability to model healthcare costs in retirement, especially since Medicare doesn't cover everything and long-term care can wreck a plan. Could you add a toggle for estimated out-of-pocket medical expenses tied to the user's projected retirement age?
@erayeepi Really good call out. Healthcare is one of the biggest wildcards in retirement planning and I deliberately left it out of v1 to keep the model approachable, but you're right that it can completely change the picture, especially for early retirees who are pre-Medicare. Adding a toggle for estimated out-of-pocket medical expenses tied to retirement age is a concrete enough feature that I can actually model it well. Adding this to the roadmap, thanks for the specific framing around Medicare gap years, that's exactly the right way to think about it. Thanks!
The side-by-side comparison is exactly what most simulators are missing, love that you used real NDCP county data for childcare costs. One thing I'd love to see is a tax layer on top, since the 4% rule doesn't really show how Roth conversions or capital gains drag change your actual FI number year by year.
@bedriye370134 You're touching on the exact line I drew when scoping the model, which is that Roth conversions and capital gains drag are genuinely important but they interact with individual tax situations in ways that would require a full tax engine to model honestly, and I didn't want to fake precision I couldn't deliver. A proper tax layer is definitely on the roadmap though, and the way you framed it, showing how it shifts the actual FI number year by year rather than just as a flat rate, is exactly the right way to think about implementing it. Noting that framing for when I get there!
The side by side scenario view is genuinely useful for stress testing life decisions. I was surprised how clearly the debt payoff timeline shifted my projected retirement age.
@kbraneyal1czd That's exactly what I was going for, less "here's your number" and more "here's what changes when you change this." The debt payoff interaction with retirement age is one of the clearer examples of that, which is why I made sure it was visible in the same projection rather than a separate calculator. Appreciate it!
the side-by-side comparison actually made me rethink my debt payoff timeline, especially seeing how it ties into my retirement age. cool that it pulls in local childcare data too
@eraysmzp Really glad the side-by-side clicked for the debt timeline. That interaction between debt payoff and retirement age is one of those things that's genuinely hard to feel intuitively but becomes obvious once you see the two lines shift. The county-level data was a lot of work to integrate but you're right that a national average would have made it feel fake for too many people. Thanks for taking a look at the app!