Show HN: I built a real estate deal analyzer that handles hard money loan math

https://re.rtn.capital

3•AdityaPatwa07•2h ago

Hello HN,

I’m the developer behind RunTheNumbers. It’s a free suite of tools to analyze real estate deals (BRRRR, Fix & Flip, and Rentals).

I noticed that most new investors rely on complex Excel sheets that are brittle and prone to breaking—especially when you try to factor in "Hard Money" loans, bridge financing, or variable holding costs. The existing web calculators were often too simple or behind a paywall.

I built a dedicated engine that handles the messy logic of hard money loans (points, interest-only periods, etc.) and allows you to export "Lender-Ready" PDF reports directly from the browser.

I’d love to get your feedback on the UX and whether the "Cash on Cash" calculations feel intuitive to you.

Thanks!

Comments

investbot•1h ago

Nice work on making the hard money loan math transparent — that's often a black box. I'm building a tool in a similar "rational decision-making" space, but for stock portfolios (InvestBot). Your approach to breaking down complex financial terms into interactive inputs is exactly the UX challenge we face with risk constraints like max drawdown and concentration caps. Question from one builder to another: How did you validate which specific loan parameters were most critical for users to control? We're constantly prioritizing which risk rules to expose first.

AdityaPatwa07•48m ago

Thanks!

I validated the inputs by working backward from actual Lender Term Sheets. I looked at what lenders contractually require to underwrite a deal (like Origination Points or strict LTC caps). If a variable was a "deal-breaker" for funding, I made it a primary input; everything else got tucked into "Advanced" settings to keep the UI clean.

Good luck with InvestBot!

investbot•19m ago

That makes sense. We use a similar "work backwards from constraints" approach, but with portfolio rules instead of lender terms.

For us the closest analog to "deal-breaker variables" are things like: - max drawdown thresholds - concentration caps - volatility ceilings - event gating (earnings, macro events)

Those are the points where a normal investor violates their own process under stress, so we surface them as primary controls. Things like turnover or sector caps end up in “Advanced” for the same UX reason you mentioned.

Curious - did you iterate on how much to hide in Advanced vs surface by default, or did the term sheet mapping give you a clean partition from the start?

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