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I built a rental property underwriting app and used it to buy a house

I built a rental property underwriting app and used it to buy a house

by OutputRiff·Mar 17, 2026·1 point·0 comments
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AI Analysis

●●SolidSolve My ProblemNiche Gem

BRRRR-specific calculator when DealCheck only does basic rental math.

Strengths
  • •Free demo mode requires no signup—try before creating account.
  • •Author dogfooded successfully, used it to buy actual property.
  • •Cash recovery and net position metrics for refinance-aware underwriting.
Weaknesses
  • •Competes directly with DealCheck and BiggerPockets calculators.
  • •Advanced features locked behind paid plans and account creation.
Category
Finance
Target Audience

Real estate investors, rental property buyers

Similar To

DealCheck · BiggerPockets Calculators · Rentometer

Post Description

Over the last few months, I built Brrrrfect.com as a way to teach myself how to underwrite properties. I've always had a relative disdain for spreadsheets and don't want to give Microsoft money for its office tools, so I decided to build this.

I think it would have taken way longer for me to get the hang of underwriting real estate if I hadn't spent time building this and really learning about what the calculations mean.

I ended up using this tool to buy my first Buy, Renovate, Rent, Refinance, Repeat (BRRRR) deal and its working out really well! I'm definitely going to keep using it for myself.

If it helped me, I figured it might help someone else, so I made it live! Right now it only supports basic residential underwriting and a more advanced BRRRR calculator, but I want to add commercial and farm land underwriting tools in the future as well.

I’d love feedback from people who invest in real estate, underwrite deals regularly, or just have opinions on what could make this tool more useful.

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